Closing the bolt problem

[Jim n Iowa]

I went to the range today to sight in and compare bullets in my newly broken in 6.5-284. I was comparing Hornady 140 sp to a Sierra 140 sbt, both loaded with IMR 4831. They both grouped -1", how ever the Hornady loads were very hard to close the bolt on. In fact 3/10 would not. The Sierra's worked fine, both shot the same groups. I have measured the lead and both loads were .010 off the lands, though different col's. I am thinking that the Hornady col is to long, as both loads use the same formed case to the same cl 2.165. Got a clue?
Jim

[clodbuster]

Jim I was having a similar problem with a rifle and found I was not getting the shoulder on my brass set back far enough.  Turns out I failed to screw in the sizing die far enough.  Several quick twists solved the problem.  Apparently the chamber was tight for length because even screwed in all the way the bolt barely closes.

[Castaway]

If you aren't lubing the inside of the case mouth that could also cause the problem when you pull the die stem out of the case.

[Jim n Iowa]

The odd thing is the Hornady 140 loads showed great resistance to closing the bolt while the Sierra 140 only showed some. They were both loaded .010 off the lands with H col =2.967" and S col =2.979". The case length was 2.165 for all. These are Win 284 cases necked to 6.5. I have some loaded with some RL-22 to compare to this group. When I lube the case I generally spray with hot shot at a 45 from 4 sides, I may have pay more attention to the necks.
Jim

[beemanbeme]

If he's using the same die and the same cases for both loadings he can't be having one that loads hard and the other easy.
 How about your bullet profile.  You say you're loading .10 off the lands.  How are you arriving at that?  Give the Hornady's another turn or two deeper into the case and see if your prob goes away. 

[Jim n Iowa]

I am loading for .010" off the lands. I measure this with a tool made by a member of this group. It is a tool that consists of the exact case for this cal.. You insert the bullet and push it into the barrel till it runs up against the lands. Retrieve the bullet, place back into the case and measure=you have the max COL for that bullet. So both loads were loaded .010" off, both COL/ Hornady vs sierra were different. I have a another load set up with RL-22 to compare these bullets, I will seat the Hornadys a tad deeper to see if there is a difference. however the Sierra loads were longer in COL?
Jim

[Lone Star]

Do the fired cases rechamber easily in your rifle?  Try a resized case without bullet.  Try a resized case without the expander stem in the die.  These tests should help to pinpoint your problem.


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[beemanbeme]

Just a thought, I don't know how closely cut your chamber is but measure the diameter of the two bullets.  Sometimes different companies cant't agree on just how wide (thick) a 6.5 bullet should be. I found .308 bullets that were .307 and others that were .309. 

[Questor]

I've damaged cases with the seating die in such a way that it would expand the case at the shoulder slightly by compressing it. It was hard to see, but it was measurable. Fixing my adjustment of the die solved the problem.

[huntswithdogs]

Jim,
Something to try here, would be to retry the loaded shells. If ya have resistance, push the bullet in a little more. Bullet construction and design may be causing your problems here.

HWD

[Jim n Iowa]

I found the problem, thanks to the guy that built it. The neck is .298, the collet on the sizing die is .294. I full sized the Win 284 case after forming it to 6.5, then neck sized (RCBS directions for new case/ golden collet dies) both using .294 collets. At his suggestion, that the brass may "sprung back". I miked the neck and found that the loaded case was now .299-.299, will not fit. Luckily I now have Lapua and Norma brass for 6.5-284 that I am now loading with. Thanks for your reply's, it was a education in forming case's.
Jim

[Catfish]

Jim,
   Any time you are playing with Wildcat you have to consider case neck thickness, espesially when you neck down the parent case. Your sizeing the neck will do you no good untill you turn the case neck. Mic the loaded case necks. I personall like to turn mine so that I have .002 of neck expantion. That means you would have to turn your neck down to where the loades case necks mic. .296. I recomand that you take 1 case and take just alittle off of it and then seat a bullet in the empty case and mic. it. If you didn`t take off enough brass you can pull the bullet and take off alittle more. If you took off to much you only ruined 1 case. Some bench rest shooters turn to chamber demention and never size their cases, but that is not a good idea for a hunting gun and some will tell you that .002 is not enought for a field gun. The main thing is to turn them all the same.

[303Guy]

Jim, out of interest, when you say you had difficulty closing the bolt, did you mean as in turning the bolt handle down or that last bit of travel where the neck enters the neck area of the chamber?

Catfish, when you say some bench rest shooters never resize their cases, does that mean the case neck retains a constant grip on the bullet or do they just have a neat fit between bullet and case neck?

 I do not resize my cases but instead, hold the bullet in the neck with a soft paper cup dipped in molten bullet lube.  I found that as long as the bullet cannot be pulled out by hand, it will work just fine in my magazine fed bolt gun.  (The cup is dipped into the hot lube after inserting into the neck, so there is a slight compression on the bullet due to the contracting neck - the bore looks like a 22lr bore and accuracy is no worse).  That's for my hornet.  My 303Brit gets the same cup arrangement but requires pressure to seat the bullet.  I did measure the 303 neck after seating and found the expansion to be minimal.  Chambering is smooth in both rifles and I no longer bother to check the chambering of loaded rounds before going out.  (I did have chambering problems initially until I got my technique sorted out – the most I get now is a slight firmness on locking the bolt). 

[Jim n Iowa]

It was closing the bolt (turning the handle down). I just loaded some Lapua case's and they mic at .294 which is the collet bushing size. I now have more than enough Lapua and Norma brass to out last the life of the barrel. The Winchester .284 was a purchase when it seemed the other 2 would be hard to obtain. Thanks for the feedback.
Jim