357 max problem

[Moe]

Need a little help. I have a 12" custom Encore barrel in 357 max shooting the 150gr R-P bullet. First two shots from a cold barrel are about two inches low. By the 6th shot its about 4-6 inches high. Cleaned barrel and let cool. Same thing again. Using H110 powder and cci primer with a medium crimp. Have used xtp's of various weights and did not experience this. Groups were not terrific with the xtps but nothing like this. This barrel uses a hanger bar forend system, shooting from a bipod. Xtps I did not use a bipod. I sometimes switch the bipod to other barrel and don't have a problem. Any suggestions? :evil:

[Paul H]

I had severe verticle stringing with my 10" 357 max contender using H 110.  You might want to try Lil gun on the faster side, or Aa 1680 on the slower side.

[Foxpro]

Although I haven't worked with contenders that long and I don't have a 357 max YET, I have encountered and tracked down three different causes for vertical stringing.

1)  Incomplete engagement of the locking lugs.  I visually check every new-to-me barrel now.  I remove the trigger group and watch the lugs engage.  You can also use a black marker to see engagement on the locking lugs, but this wasn't as good as seeing it in my opinion.

2)  Cases too long - need shoulders pushed back a little (bottleneck cartridges).  I've avoided this longer by slamming the action shut firm and consistently.  I guess this could be a problem for rimmed cartridges if the rim does't fall below flush.  

3)  Lil'gun powder in a 22 hornet carbine.  Extreme spread was over 100 ft/sec.  Got a chronograph?

Hope these ideas help someone.

[PaulS]

Moe,
I have noticed that all my contenders are real sensitive to the amount of down force I use on the fore-end. As I shoot I tend to put more pressure on the gun and the shots begin to string up. The opposite happens when I shot a revolver - after a while the shots begin to hit low. I won't try to explain it but it is my experience.

PaulS

[Nobade]

Don't let the butt touch anything, it'll do that as well.

[T/C nimrod]

Ok, I've heard that enough times to question now - don't let the butt touch anything? Help me out here. I bench shoot the Contender frame off sandbags supporting the butt of the gun(s). Can't say this has ever effected the precision and/or accuracy of what I've shot this way. The other thing I've taken notice to are the long range rest systems for the Contender/Encore - all have butt supports.

Now, I do not consider myself a long range handgunner, (minus the few attempts at such), but I feel that their practices would be effected more by their rest (system) then the average shooter. Please set me straight on this.

[Crayfish]

I agree with you T/C Nimrod ... I always use a sand bag under the grip when shooting my T/C's from the bench.  Not only do they shoot remarkably small groups, the point of impact is also consistent with hunting positions (braced against tree, etc).  I see no ill effects when using this method at the bench.

Now, the Bower system looks like solid wood against wood.  If THAT works as well as it does, I don't see how letting the grip touch something (as long as it's CONSISTENT!!!) will make any difference in the group sizes.

... Crayfish

[PaulS]

Having the butt of the Contender resting on sandbags is ok IF you always have it resting on the bags. If you shoot in the field or without supporting the butt of the gun it will shoot lower than it does when rested.

PaulS

[Moe]

Guys, I was resting the butt on a sandbag with considerable force to "nestle" it in. I have done this before, including yesterday with a Contender also, no problems there. I have another frame(Encore) that I think I will try with the H110 loads. I have a hunch this may be the problem. More opinions? 6" groups are not acceptable. :x

[Moe]

Went out again using another frame. Same thing. LOaded some other rounds with H4227(what I had on hand), and two different primers. Also took some 140gr. xtp's I had loaded. Tried at 50 yards first the 150's where almost in the same hole. The xtp's a little wider. Moved out to 100 yards and everything opened up again. But not near as bad as the H110 loads. I think my scope is part of the problem. I now think nothing is wrong with it, other than its not as clear or as easy to sight with compared to the others I have. So when I move out to 100 the sight picture is not that good. I will do more work.

[Moe]

Well, still working on this. I have tried two frames, two scopes, two forends, two powders, two primers, about four bullets, seated to different depths, various crimps. Was out yesterday, at 65 yards all loads of all combinations shoot one ragged hole. As soon as I go to 100 yards I have 6 inch groups again. I was even able to hit a rock the size of my head at an estimated 200 yards with the first shot, but not at 100 yards. Bullet weights ranged from 125-180 grain. I have done everything suggested by this board and friends except bed the forend. If that is a problem I would think it would be at 65 yards also. I also found out that the barrel is a 1/18 twist. Guess I better specify next time I order a custom barrel. It is wonderful to shoot and I would not hesitate to deer hunt with it, but at closer range. The two powders I have used are H110 and H4227. I will try some others in the future. Thanks for the help. :cry:

[Javelina]

Hi Moe,

You and I have discussed this at some length and I'm sorry to see that you're still having big grief with this thing!

I have given this some thought and have some nagging questions in a couple of areas, some mentioned by others and some not.  If you’re using a hangar bar now, I would not glass-bed the forend just yet – but I would check the two hangar-bar screws to be sure they’re not too long.  If the hangar-bar screws are too long, they can definitely give you problems.  To check this out, you’ll have to remove the forend, hangar bar and the two dove-tails to see if there are any circular marks on the underside of the barrel in line with where the hangar-bar screws might make contact with it when they’re tightened down.  If there are marks present, file or Dremel the hangar-bar screws a little to allow clearance when they’re tight.  If you want to change your screws to stainless cap screws, they are easily obtainable for Contender barrels (not Encore barrels) at Ace Hardware and I have personally bought them at the Ace at Sabino Canyon and Tanque Verde if that’s of help.

I wonder about bullet stabilization (or destabilization) at 100 yards being an issue.  Sometimes this can happen with certain manufacturer’s bullets and not with others.  It can take some real experimentation to get past this.  Bullet designs being what they are, each manufacturer’s bullets can have a different weight distribution, design, jacket hardness, etc. which can effectively alter their flight characteristics.  Since you get acceptable groups at 50 yards, the only real way to investigate further is to shoot at 200 yards to see what happens.  To do this you'd have to go to 3-Points or Pima Pistol Club, they have 200 yard ranges.  Just a thought.

I’m not generally big on the hinge-pin issue, since it’s hardly ever been a problem in my experience, but are you using the same hinge pin when you put the subject barrel on a different frame for testing?  You might try switching hinge pins if you have more than one you can use.  It may even come down to obtaining and having on hand one or two various oversize hinge pin sizes for testing various barrel combinations in the future.  This is just more food for thought.

Try different powders per other suggestions, and really use the full spectrum (lowest to highest) of load recommendations in the reloading manuals.  Sometimes you can overcome bullet stabilization problems (or at least affect them to a significant degree) by simply varying the velocity which directly affects the rate of rotation (spin).  Varying the rate of rotation can often have a pronounced effect on bullet stabilization characteristics.  The only way to find out how much better you can do with a given bullet is to slow it down (don’t do this with H110 or W296 [same powder] since they generally have such a small optimum window and can be dangerous if loads are reduced too much, sometimes reductions of even 3% can be too much) in flight using the lowest recommended loads and working up with several different powders including the fastest and the slowest powders recommended in various reloading manuals.

Just for grins check your muzzle crown carefully, any damage could be detrimental to accuracy.  Also you might want to recheck the ocular focus on your scope to make sure it is as clear as you can get it and also that it's locked down tightly.

Stay with it bro’, you’re going to get ahead of this thing yet!   :grin:

Stay in touch.

Javelina

[Moe]

Javalina, yes I have different hinge pins specific to each frame. Also tried the scope focus. If I ever talk to you on the phone I will explain the "second" scope scenario that I tried. I will check the hanger bar screws though, that is a good idea. Thanks again for all the help everyone. I guess I will try some of the other recommended powders before to long. I just finished loading some more variations of the components on hand. We'll see. I have not given up just yet.

[TheKid]

I know you said you changed the scope, but this almost sounds like a parallax problem.  I have a 581 Remington that has a cheap 3x9 Weaver on it and at certain ranges it's so bad you can't hardly see thru it.

Just a thought, I'm no expert!

Good luck
Gary