brass shavings on bolt face

[jps120]

I am using Varget for powder, CCI 450 primers, lapua brass, and this is what I was using before when shooting 105 vld bergers at 29.5 grs. It did give good accuracy for me. I wanted to try the amax bullets cause they are more available and cheaper. When shooting the VLD's there was no brass shavings but the primers still had cratering. I switched to the Amax and dropped the powder down to 28.5 and started working up from there. Like I said there were faint ejector marks on the 28.5 gr rounds and very noticeable marks on the 29.5 gr rounds. Larry I don't see the bolt face not being square to the chamber as the action and bolt were trued and squared to the barrel by the gunsmith who built the gun.

 

[Ledd Slinger]

The main thing to remember is that you are in dangerous territory right now. Proceed with extreme caution. Best thing to do would be to just back off and try to find a good accurate load at 28.5gr or lower with the A-Max. Every time you push the envelope to pressures you know are too high, you risk serious injury.

 

[jps120]

will do

 

[/VH]

jps120,

I agree with Ledd Slinger, I think you need to back down and eliminate the ejector marks completely. Also, I don't know where you're located but even though Varget is an extreme powder, I'd sure be careful/conservative working up a load now if you're expecting to be shooting in warmer temperatures.

Looks like changing bullets made a significant change in your pressure.

 

[CatShooter]

Looks like the bolt face s not true to the chamber. Check the bolt . I think you will find all the pressure on one lug. Larry

There is nothing that indicates that the bolt is not true... the bolt is fine from what can be seen.

 

[savagedasher]

Looks like the bolt face s not true to the chamber. Check the bolt . I think you will find all the pressure on one lug. Larry

There is nothing that indicates that the bolt is not true... the bolt is fine from what can be seen.
[/quote Josh and I talked on the phone. He took a case that fit tight. Cleaned the lugs an use Sharpie on the bolt lugs using the tight case for tension. He found only one lug wore the Sharpie . My advice was to have a gun smith check it. Larry

 

[LCazador]

JPS you state that your loaded cartridge headspace is 1,164 and that the fired cartridge is 1.166 and then you further state that you should be bumping the shoulder back. The difference between the two measurements is .002" which means you are bumping that shoulder .002". That is an adequate bump and should be no more than that. With that said there is quite a difference in ogive dimensions between the two bullets, one being more secant than the other which is more tangent. That is going to result in quite a jam into the lands and much higher pressure. You need to revisit your starting load parameters and back off! Like others mentioned there is nothing wrong with your bolt, you just need to back off or change powder. Varget seems to be a very fast powder for 105 grain bullets.

 

[jps120]

I agree there is a big difference in the ogive dimension but even if the Amax has a longer dimension to the ogive the same amount of bullet should still be engaging the rifling and the extra length would be into the case, right?. I guess I can't see how the amax would be anymore jammed than the vld if they are seated to the same ogive dimension.

 

[Patch700]

the extra length would be into the case, right?.

You may have just answered your own question lol.... I have had some calibers with certain throat lengths where when the load was worked using a particular powder and primer the load got hotter as the bullet came off the lands (reduced case capacity and double based powder) I realize this goes against common theory that stuffing bullets raises pressure but in that case it was the decreased case capacity that showed the most noticeable sign.

I stumbled onto it during a test session chasing the lands and when I got to .015" off things started to look warmer than jammed (Near compressed powder charge in this case)

Perhaps you have more A-max taking up boiler room than you think?

 

[Drop Port]

All good sound advise which may well be correct, mostly correct or partially correct. Something doesn't smell right. Curious as to your set up free bore, barrel round count etc.
You have cratering on one side of the pin, yet round edges on the primer, even with a tight fit pin I get squared edges on primers (pressure) with no cratering. I have had Rems crater on low end loads before. Also had extractors shave brass on low end loads. I even had one with an ejector hole with bur that showed false pressure readings.
I would be curious as to crony readings, your load is extremely light compared to mine, may be pressure, also could be contributing factors. Wouldn't hurt to have a reputable smith look it over in person, sometimes a picture helps but isn't worth a thousand words.

 

[LCazador]

I agree there is a big difference in the ogive dimension but even if the Amax has a longer dimension to the ogive the same amount of bullet should still be engaging the rifling and the extra length would be into the case, right?. I guess I can't see how the amax would be anymore jammed than the vld if they are seated to the same ogive dimension.

I don't how your seater is set up but the punch on your seater is going to engage the different ogives at different points and give you different seating depths for each configuration of bullet.
Also your measureing tool does not measure to the same ogive point where the bullet actually contacts the lands. The bullet with the longer ogive will contact more of the lands and will be jammed more. So you should have two different measurements, one for the secant ogive and one for the tangent ogive. This is also one of the reasons tangent ogive bullets are more difficult to tune. See Brian Litz's book on this. Also because you are deeper in the case, you have also reduced the powder room and therefore you're developing more pressure.

 

[mousegunner]

I get brass shavings just cycling dummy rounds. I have a new bolt with extractor and ejector. I think the extractor has a sharp enough edge since its new that its causing this but otherwise I don't think its an issue.

 

[Ledd Slinger]

I get brass shavings just cycling dummy rounds. I have a new bolt with extractor and ejector. I think the extractor has a sharp enough edge since its new that its causing this but otherwise I don't think its an issue.

If you remove the extractor and ejector, you can clean up all the rough edges of the bolt and extractor claw with some 400 grit sand paper. I like 400 grit because it will soften the sharp edges and still leave a fairly polished finish. If you really want it smooth, hit it all a second time with some 600 grit. Just a thought.