rifling marks on ogive

[Scibaer]

i chambered a few ( most ) of my handloads for the 45-70. a few of them ( 2 or 3 ) had rifling marks on the bullet.  the col and dia were the same as the rest but only these few had marks from the rifling on the ogive area...
 will this hurt or make any real difference to shoot these ?
 the weather is goin to be in the mid 30's over the next few days and i want to get my BC sighted in, i got a pig hunt coming up in march
glenn

[Catfish]

Looks like you have a small variation in the ojive of your bullets. Not sure how it will effect your accuracy, but it could be quite a bit if it`s enough to increase the bullet pull on the different rounds and hence chamber pressure. I would set the ll back another few .015 if you have to go far to shoot. If your like me and just step out the door and shoot I`d shot a group making sure I had I had a 50-50 mix of long and short.

[stimpylu32]

Glenn

Something is amiss , are these cast or jacketed bullets ?  Are your loads close to max ? The reason i ask is that you could see an increase in pressure with the bullets seated into the lands , how much will depend on the powder charge and bullet style .

Are these the bullets that i sent you by chance ?  and what is your COL ?

stimpy

[Scibaer]

richard,
 these are the cast lead  you sent me. the 405gr. cast fn's.
the brass trim lenght is  2.10 in.
 the c.o.l. is 2.52
i loaded them real mild with 28.0 grains of H4198 using winchester brass and primers. i was loading for a plinking ( getting to know the gun and handloaded rounds ) round.
i test fitted every round i made up and i saw the rifling marks on 3, all from this 'lot' and no others..

Catfish,
 i have been known to shoot guns inside the house on a few occasions, but no i normally have a 10 minute drive to shoot anything substancial

[corbanzo]

Did you recheck the col?

Are they roll crimped per chance?  I had some .454 WLNGC's that I checked the col after the bullets were seated, but my roll crimper didn't like the bullet and threw a couple off. 

[Castaway]

You need to be careful.  If the rifling is engaging the ogive, you're about a half step away from the bullet being pulled upon extraction.  Since you're loading very mild, seat another smidgen and you should be fine.

[Scibaer]

Yes, they are roll crimped with a RCBS die.
yes i rechecked the COL, on the ones with the problem, they measure 2.53 in.
 i guess thats just too long for my chamber, i have specs that say 2.55 is max, but my rifle must be under spec.

 i believe i cannot seat deeper with the crimp on, or am i wrong ?
at that load the pressure should be ok, but the accuracy is probably crap, right ?
glenn

[LaOtto222]

H&R 45-70 are notorious for short throats so you must be careful about OAL. Most precision bullet seaters work off of the octave to ensure uniform bullet seating. If you have a wide flat nose on your bullets, it maybe seating them off of the end of the bullet. When you do that the OAL length will remain the same but the octave distance from the lands will vary due to slight differences in the bullets. Even good quality jacketed bullets vary in length from one to the next. Maybe most of your bullets have a small parting line and the three you had touching the lands had none, allowing them to reach the lands. It may effect your accuracy or may not with cast bullets. To be safe, I would turn down the seater a quarter turn or so, to make sure they are not touching.

[Castaway]

Single shots don't need to be roll crimped.  A taper works just fine.

[corbanzo]

Yes, they are roll crimped with a RCBS die.
yes i rechecked the COL, on the ones with the problem, they measure 2.53 in.
 i guess thats just too long for my chamber, i have specs that say 2.55 is max, but my rifle must be under spec.

 i believe i cannot seat deeper with the crimp on, or am i wrong ?
at that load the pressure should be ok, but the accuracy is probably crap, right ?
glenn

Seating further with the crimp on will make the crimp useless for the most part, and shave off a little lead, but shouldn't cause any real problems, especially if you are going down only a couple hundredths of an inch or so...  I've done it, just don't OVER-do it  Could throw accuracy off too, changes the uniformity...

[corbanzo]

And also - is it all matching brass?  Could there be some with a thinner rim?

[Scibaer]

yeah all matching brass, same lot and checked, sized and rechecked.
i re-seated the 3 bullets in question .02 deeper, it did shave a very small amount off 2 of the 3
i rechambered them and i dont see any new rifling marks so i guess its good to go
should be good enough for plinking
thanks for all the help, tomorrow morning im going to shoot some, zero in the scope.
i'll give a range report
glenn