FA83 - Undersized cylinder throats

[Humbo]

Hi!
I always assumed the throats of my M83 .454 Casull were according to FA specs at .452 diameter. I bought a couple of molds from Veral at LBT, one 340 grs WFN and a 300 grs LFN. I slugged the bore before I ordered, it was exactly .452. But when I tried to feed ammo with those 340's, I just couldn't get them to chamber. I've never had any problems with this before, I've mainly used the RCBS 300 grs SWCGC bullet earlier.

At first I thought it had something to do with not full-sizing the brass, but I tried that, and the problem persisted. I then tried to drop some of those bullets sized to .452 through the cylinder, and there was just no way they would go through. Even .451 was too large. I guess I haven't noticed this before because of the short nose-to-crimp length of the bullets I've used so far. From this I assume that the throats of my 83 are around .449 or 450, which is way too small. Is there a simple solution? I really don't want to send my gun back to FA, I've heard it's quite a problem to ship guns into the US these days.

Thanks!

[Wiking]

I've been told that shipping a gun into the US for repairs isn't difficult. I too wanted to ship mine back to FA, nothing wrong with it, just wanted some custom work done. Anyway, I'd heard that it was nearly impossible to get it into the country... so I dropped my plans, but was later on told that it doesn't apply in regards to repairs.

[stuffit]

Be sure and micrometer your bullets AFTER you've sized them in your bullet sizing die.  With some hard alloys (linotype will so this sometimes) you'll get some rebound after sizing.  When I was casting for my FA 454 early on, I found that I had to size some linotype in a .451" H&I Lyman sizing die to get it to .452".  Other alloys gave bullets of the size designated on the die. 

I'd also suggest that it is a mistake to measure your chamber throats with the "trial" method and  compare it to the "slugging" method used for getting the groove diameter.  If you remove the cylinder, it's not difficult to use soft lead to slug the cylinder throats if you proceed cautiously.  Your "assumptions" regarding your cylinder throat size may well be correct but I'd cover all my bases before contacting FA in that regard.
 
stuffit

[Humbo]

Wiking, stuffit, thanks for the replies.
I will try to slug all throats and see if my predictions were correct. I measured the bullets after I sized them and they all measured .452, with ww alloy. I also tried with 4 factory bullets, from Nosler, Hornady and Swift, and they were all too large, even the .451 bullet from Nosler.

I'm going down to my furnace right away to prepare some pure lead solids for slugging purposes. I will keep you posted on the results 

Humbo

[stuffit]

A couple of afterthoughts.  I didn't notice in your first postwhen first reading it,  but it sounds as if you may have successfully used factory loads in your revolver?  If this were the case, then other avenues might need to be explored to provide an explanation.  If not then we're back to "GO".

Another chambering problem I ran in to in the early days of the FA 454 was caused by a slight expansion of the "outside the brass" part of the older Hornady JHP when seating them over what turned out to be compressed loads of powder.  The jackets were too thin (since corrected by Hornady) and bulged enough to prevent chambering when seated, even though properly crimped.  I suppose I'm rambling now as this wouldn't apply to your cast loads, I'd not think.  Just keep in mind that the old addage, "if something can go wrong, it will".  It's amazing what gremlins lurk around for the sole purpose of creating "confoundment" or, perhaps, creative thinking, depending on your point of view
 
stuffit

[Graybeard]

I SERIOUSLY doubt FA let one out with throats off that much. I'd be sure to have them properly measured before thinking of a return. If they really are tho you should only have to return the cylinder I'd think.

I suspect that if you properly measure them with pin gauges they will be .452" to .4525". If they aren't call FA and ask for them to open them to proper dimensions and as I said the cylinder should be all they need.

[Humbo]

GB, you were right, throats weren't as small as I suspected. I slugged all of them, and they measured .4515 from a Starrett calipher. I will try to get ahold of a pin gauge or a micrometer to get if possible an even more exact measurement before I return the cylinder for opening. If the cylinder is all they need, it will save me alot of trouble and money. The throats are still too small to use those heavy LBT bullets though.  I even pulled some of the bullets and tried the brass in the cylinder, they chambered just fine.

stuffit, I actually never fired anything but reloads in my FA. Cheapest .454 factory ammo around here is close to 2 dollars a bang.

[paul105]

Humbo,

I have a .454 that I bought about 20 years ago.  I struggled with it off and on over the years due to what I thought was tight throats.  FA Factory 300gr ammo had to be forced the last bit into the chambers with heavy finger pressure.  A year ago (yeah, I have a high tolerance for pain -- actually just lazy) I needed some work done to my M97 and mentioned the tight throats on the .454 to John at FA.  He had me send the .454 cyl in along with the 97.  When it came back the tight throat problem was fixed.  The original throats were extremely abrupt (no chamfer/taper at the rear of the throat).  From what I remember, FA chamfered/tapered the lead into the throats, but didn't open them up.  The throats will let a .452 bullet pass but not a .453, so call them .4525.  We slugged the bore, and it is right at .453.

So, my first suggestion is to see if a .452 jacketed bullet will pass thru the cyl throats from the rear of the cylinder.  If not, see if they will pass thru from the face of the cylinder – if they do, you may have the same problem that I had.  If not, you’ll probably have to use cast bullets sized .451 just so they will chamber.

In my experience with the FA 475 LB (and the fixed .454), any of the Keith SWCs with the wide front drive band above cyl throat diameter are virtually impossible to seat in tight throated cyls.  The LBT WFN with the longer (relative to a shorter nose in same caliber) nose to crimp measurement can also be difficult to seat.  The WFNs from Cast Performance, as well as some of Leadhead’s bullets seem to be dual diameter – the base will be larger than the portion of the bullet in front of the crimp grove – so no seating problems.  LFNs, and RFNs seem to be less prone to sizing/chambering problems.  Unfortunately, about the only way you are going to figure it out is to actually try different nose profiles, manufacturers and diameters.


FWIW,

Paul

[Humbo]

Paul, thank you for the reply.
I've tried with different jacketed .452 bullets, none of them will pass through my cylinder. I even had some .451 (measured .4515 with my calipher) that wouldn't go through. Unfortunately I don't have a .451 sizing die, but I will try to get one soon. Bullets get stuck, both from the rear and the front of the cylinder. It seems tighter in the rear though.
I just tested with another jacketed .451 bullet, I could push it through all chambers from the rear with a little bit of resistance. Dropping it into the chamber from the front, and it got stuck, and I had to push it through like from the rear. Seems like my throats are between .451 and .4515 somewhere. Are they off enough to get them opened up? If my bore is .452, then what is the ideal throat size? My FA is a lifelong dream come through, and I really want it to be perfect. If there is something to gain from opening the throats up by only .0005, I'd be happy to get it done. I'm gonna be buried with this gun. 

And if I get all the papers in order, I can soon send an order on a 97 .45 Colt with a 5.5" barrel. Hopefully barrel/throat dimensions will be exactly the same as on my 83.

[paul105]

Humbo,

My .454 has a .453" bore and as best as I can determine .4525" throats (.452" bullet passes easily, but .453" bullet won't), and it will put selected loads into one hole at 25 yds.   In fact one of my most accurate loads in this gun uses the the 270gr RCBS SAA SWC sized .454".  This load has to be crimped over the front drive band when using .454 length cases or the .454" front drive band hangs up on the cyl throat and won't chamber.

If I were you, I'd try to find a load that works without resorting to opening up the throats.  I'll bet, that with a little experimentation, you'll find a load that meets your expectations.

Paul 

[Hank08]

Humbo,
You said that the RCBS 300 swcgc worked ( I shoot the same bullet in mine) so I think the throats are fine in diameter but the lead into the throat isn't large enough for the LBT bullets.  The LBT bullets are designed to put a lot of the weight
outside the case which means they are too fat and stick in the throat where the RCBS
swc is tapered.  My 83 shoots so good with other types of bullets that I don't wont to change anything so haven't opted to change the lead into the throats to make room for the LBTs.  I can use the LBTs by seating them deeper into the case but the charge has to be lowered to compensate for the smaller case capacity if your already at max.
H08

[Humbo]

Paul, my next question is, won't shooting .451 bullets in a .452 bore affect accuracy or lead to excessive leading? I have to be able to shoot those heavy WFNs, and not having feeding problems, because next year in going hunting in Africa with them. To make them feed properly, I have to at least size them down to .451. With lighter bullets with shorter noses I haven't noticed any problems.

I'm still waiting for an answer from FA, hopefully they can shed some light on this.

Hank, that's right, the 300 grs RCBS is almost the only cast bullet I've used so far. Accuracy is good, but I wanted a heavier bullet with a longer nose-to-crimp length for maximizing powder space. I ordered some molds from Veral at LBT, and I really like his designs. The 340 WFN (actually 360 after sizing and GC) has a .4 nose length, and base-to-crimp length is about the same as the RCBS. LBT also has a much deeper crimping groove. I've had some crimping problems with the RCBS, after sizing parts of the groove is just gone, and a proper crimp is difficult to obtain. I suspect my mold oversizes a little bit, but I haven't done anything about it.
Anyway, maybe you're right about the throats. But if my throats were .452, shouldn't the bullet feed properly no matter what if I sized it to that dia? Throats are measured from the tightest spot, which means the rear, if I'm not mistaken?

Humbo

[paul105]

Paul, my next question is, won't shooting .451 bullets in a .452 bore affect accuracy or lead to excessive leading? I have to be able to shoot those heavy WFNs, and not having feeding problems, because next year in going hunting in Africa with them. To make them feed properly, I have to at least size them down to .451. With lighter bullets with shorter noses I haven't noticed any problems.

Humbo,

I honestly don't know.  Obviously, it's not ideal.  The only way to know for sure is to give it a try.  As mentioned above, the WFNs are full diameter for a good ways in front of the crimp grove and tight throats can cause chambering problems with them.

How much of the case remains out of the cyl when trying to seat the case in the chamber?  If it is considerable, ignore the "dummy round" suggestion that follows.

Set up a dummy round.  Size a case, seat a bullet (no primer, and no powder) to the crimp grove and crimp just enough so the case will seat in the chamber.   Continue to seat the bullet deeper in the case until it chambers in the cyl.  It might turn out that all you need to due is moderately trim your cases.

If long distance phone calls are not too expensive from you location, call Freedom Arms direct (307-883-2468) and ask for John -- he is very helpful.

Paul
   

[Humbo]

Paul, I can chamber the round down to the case rim, so I guess a couple of mm doesn't fit in there. I don't think it's a problem with my brass, I've measured them to be 1.365, and they chamber just fine. I will try your dummy round suggestion anyway though. Your help is greatly appreciated! Maybe I'll call FA tomorrow if they don't answer my email.

Humbo

[Graybeard]

I've sent this topic to Bob Baker via e-mail. He will most likely drop in and comment when he has time. He doesn't visit real regularly due to his schedule but is pretty good at dropping by when I send a post to him for review.

[Humbo]

Graybeard, thank you very much! I really appreciate all the help from you guys.

Humbo

[Lloyd Smale]

FA guns have tight chambers. tighter then about anyone else. Its one of the reasons they can run the pressures they do and why brass will actually live to be reloaded again in them.  Down side to this is ammo has to be in spec or it wont work and you have to be pretty meticulous about keeping your chambers clean. Becuase there so tight a slightly out of spec set of dies or even a tad to much crimp can cause problems in ammo chambeing in them. It can be a fine line between to much crimp and not enough. Also like was allready said some bullet designs just dont want to work in them well. I really like the rcbs 300swc. Its probably my favorite 45 cal bullet. Ive killed lots of game with it at about any velocity a 45 can be run at and have never found it lacking. I guess if my gun shot it well i wouldnt worry much about running something slightly heavier or slightly faster. Its plenty enough bullet for the 454 as is. I also wouldnt worry to much about throats that went .4515, about any alloy of lead will bump up some at an speed and thats a small ammount. I guess unless i was getting poor accuracy or leading i wouldnt loose any sleep over it. Ive got a buddy and he comes on this forum and hes a tad anal about his guns. First thing he does when he gets one is starts measuring everything and looses every bit of confidense he has in the gun or the builder. I tell him all the time that the first thing i do is shoot the hell out of a gun if it shoots welll a measuring device never needs to touch it. If it doesnt ill try a few tried and true tricks to get it to shoot and only if they fail do i start measuring throats and barrels. Personaly if a gun will shoot a one inch 25 yard group i dont care if i have to pound bullets throught the throats with a sledge hammer.

[Humbo]

Lloyd, I guess you can say that I'm anal about my guns, especially my FA. I've bought several custom molds for my .454 which weren't cheap, and I really want to be able to use them. I don't know how much it will run me to get FA to open the throats, but I have no doubt that it'll be worth it. I think the ideal throat size would be .4525, then I shouldn't have any problems with any of the molds or jacketed bullets I've bought.
Today I cleaned my cylinder again, very thoroughly. I'm not sure if it helped, but it sure didn't hurt. But there is still just no way I can get those WFNs to chamber. I tried with a dummy round, from no crimp to a heavy roll crimp, with no luck. It didn't matter how much I crimped it, the only thing that helped was seating the bullet deeper, past the crimping groove. Nose is just too fat.

Humbo

[Humbo]

Received an email from FA 15 minutes ago. They will have a look at my cylinder, so I guess I'm shipping it ASAP. Does anyone know if there are any restrictions on sending gun parts into the US? What do I write for customs?

Here is what FA wrote:
"It would be extremely unusual for the cylinder throats to be undersized but if you send in your cylinder we will check it out and open it up accordingly.
 
Sometimes there ends up a slight restriction at the junction between the chamber and throat.  If this is the case we will put a slight taper in that area.  Send us a dummy round of what you are trying to chamber so we can make sure it will fit."

Again, excellent customer service from FA. I can't wait to order another!

Thanks

Humbo

[paul105]

+1 -- FAs customer service is absolutely first rate.

Paul

[Lloyd Smale]

its perfectly legal to send your cylinder in the mail.

[Bob Baker]

Thanks Graybeard.

Humbo and I have exchanged a few emails to get it sorted out.  The biggest problem is he is in Norway so we need to work within the rules of the different governments.  We may even be able to get it taken care of there.

For every problem there is a solution, some just take a little more thinking.

[Humbo]

That's right, Bob has been very helpful. I will try to find someone who can help me with the needed forms and formalities. If it turns out to be very difficult, I will have to try to find a gunsmith here in Norway that I can trust enough to let him work on my FA.

Hopefully it won't be too difficult.

Humbo

[Humbo]

I'll be damned, I guess I owe someone an apology. 
Finally got me a reliable electronic micrometer from Starrett, sent all the way from the US. It should be good stuff and I don't have any reasons not to trust its readings. To be sure I ordered another one, which should be here next week. I did not try to slug my cylinder again yet, but I've done some measuring here and there. I measured some of the bullets that I just couldn't chamber, and they were about .453 or very close, even right after running them through an RCBS .452 sizing die. How's that possible? Is it something wrong with my die or the alloy I use? When they say .452 I thought they meant .452. I have some Hornady XTP mag's, measured to about .45215 or .45220, and I could actually push them trough all chambers in my cylinder, with a little bit of resistance. Now I have ordered SAECO .451 and .452 and RCBS .451 dies, so I should be covered on that front. I'm just happy that I didn't do anything hasty about my cylinder. Thanks guys.

[Graybeard]

Spring back is why bullets don't necessarily read what the die they went thru does. It's just a fact of life.

I'm glad you finally found out your gun was correctly made as I suspected from my first post on this thread. I won't say it would be impossible for one to get out of FA wrong but I'm betting it would be a darn rare thing. Their quality control and precision workmanship isn't matched by any other gun maker I'm aware of.

[myronman3]

spring back is a p.i.t.a..   but a fact none-the-less.   two solutions...i find i get more springback when i cast using pure w.w..  mix with 50/50 ww/plumbers lead and springback isnt such an issue.  the other obvious answer is to get smaller diameter sizing dies.  i had this problem with my f.a. 44; or truthfully stated i had this problem with MY BULLET CASTING METHODS.   like lloyd said, they have tight chambers.  it really makes you aware of the details.  lol.

[Humbo]

myronman, don't your bullets get too soft with that much pure lead in them? I like my bullets hard, for magnum velocities, and use only ww. I guess I'll have to size them down .0001 more.

[Lloyd Smale]

springback can be a problem with higher antimony alloys and another thing ive ran into alot is dies arent allways what they are stamped. Ive got a 452 die that sizes 453 and a 453 die that sizes 452. go figure.

[Humbo]

Are there die manufacturers that operate with tighter tolerances than the competition? I already have an RCBS LAM2 and a SAECO sizing press, and decided to try out a Star as well. I've heard many good things about them. Those heavy 360+ grains LBT bullets are really hard to size, especially on the return stroke, so a push through sizer should make it a lot easier.

[myronman3]

myronman, don't your bullets get too soft with that much pure lead in them? I like my bullets hard, for magnum velocities, and use only ww. I guess I'll have to size them down .0001 more.

it was never an issue for me.  my bullets would be pretty hard, or at least hard enough to punch through an old county plow when mixed at 50/50.  leading wasnt an issue.  i think  guys are hung up on how hard their bullets are more than they should be.  harder isnt always better.  the only reason i switched to pure ww is that i wanted to save the 300lbs of plumbers lead i have.  and when i made that switch is when springback and me met each other.   
   some to think of it i lied, i was mixing two ingots  of ww to one ingot of pure lead.  and there was no noticable springback.   you will have to forgive me, it has been a year or two and alot has happened since then.  but for sure, i was mixing two ww to one pure lead.