Hello to the list:
I just a 98 FN Mauser back from a local gunsmith(???)after bedding a McMillan stock and some other action work. It was a Shilen barreled action when I picked it up. Took it to the range on Friday and again this morning and am having a definite problem I hope you guys can enlighten me on. I tried 2 different factory loads and 3 sedate reloads and on all of them raising the bolt was from hard to difficult. No flattened or cratered primers were noted nor any other sign of high pressures. Extraction was not difficult once the bolt was raised. Any ideas as to what would be causing this? Gunsmith(?) claimed he had no problems when he test fired it prior to bead blasting and bluing and said headspace was very good. There is a definite problem and don't know whether to take it back to bubba or not? Thoughts?
Thanks,
BJB

just a guess now....this is a symptom of lug setback.

Headspace can appear good with this problem.

Bear in mind that I'm purely guessing but if I'm right (I hope not) the action may be junk!!!

I hear it can be cured.....the fix is very expensive.

hold on here fellas...
first things first

BJ,
make damn sure the gun is empty...
dry fire...
see how hard the bolt is to open.

now, loosen the rear action screw.... (a lot) - might have to take it out of the stock

repeat...

if much lighter, the trigger is bottoming out on the triggerguard, or dug into the stock......

Jeffe,
I tried that and I think that the front of the timney trigger was making contact with the bedding material. I relieved it and it seems to make a big difference. Hope that solves the problem.
Muchas Gracias amigo
BJB

If you're using a Timney trigger on a Mauser, make sure you have a sporter type cocking piece. By this I mean the cocking piece should be solid on the bottom, not dished in the middle. If you don't know what I mean, let me know and I'll try to dig up a pic. Using a military cocking piece with a replacement trigger can cause hard bolt opening.

Sam B.

quote:

Originally posted by BJB:
Jeffe,
I tried that and I think that the front of the timney trigger was making contact with the bedding material. I relieved it and it seems to make a big difference. Hope that solves the problem.
Muchas Gracias amigo
BJB

de nada, ese es mi trabajo!

make sure when you screw it together the bottom of the trigger housing isn't pressing on the guard, as well.

bubba bit, Bubba fixed

bueno suerte
jeffe

Friends-

I have a question for Vapodog and jeffeoso. Can you identify lug set back by physical inspection (i.e. just looking at the lugs on the bolt) or do you have to shoot a rifle in order to identify lug set back?

Thanks in advance.

Lug set back won't be apparent looking at the bolt. What happens is that the receiver is soft and the locking lugs set back into the receiver causing a slight depression in the locking recesses in the receiver itself. When you fire a round and try to lift the bolt, the lugs are trying to actually move forward against the fired case to cam out of the indentations made in the reciver.

Lug setback is not a feature seen on the bolt. It's found in the action where the lugs of the bolt have been driven into the receiver as a result of a "too soft" (or too much pressure of the cartridge) action.

Since the setback is only in the area the lugs engage in during firing the closing position of the bolt is unaffected and hense the no go gage will not go as it's supposed to.....giving the impression that there's not a problem of headspace.....when in fact there is and quite a bit.

What happens is that the brass grows in firing to fill the chamber but upon opening the the bolt the case must be crushed foreward somewhat to open the bolt causing the bolt to not want to open.....or open with quite a bit of resistance......if at all.

The most blatant symptom of setback is a hard to open bolt even with very mild loads.

I believe this is a rare condition and is found mostly on sporterized Mausers in .270, .25-06 etc. where the pressures of even factory rounds is considerably greater than the original 8 X 57 loads the gun fired originally. 1909 Argentines seem to be affected more than others.

I've never seen this condition in a Remington, Winchester or any other modern action....only Mausers. But then Mausers are sporterized 1000 times more often than any other action too.

lug setback..

the is actually an issue with bolt THRUST not merely pressure...

it would be nearly impossible to have this happen on a 223, but a 550 express might could do it (haven't seen it yet)

when the bolt is all teh way closed, but it can move back, when fired.

i have not seen this happen, to date, but the day is young.

i think this is like the heat treating on springfields.. a VERY real issue, with a VERY limited occurance.

cocking pieces can help, if you have a commercial.. but won't stop you from working

jeffe