Modifications for precision rifles

[Spishack357]

Brilliant, I take it that you took the videos?

[Tomcat088]

Thank you for the compliment. No, I did not take the videos, but I wanted people to be able to see and better understand the processes that I was talking about. So I searched and looked around and found those and they were quite good. I would never want to take credit for something that I didn't do, so if you enjoy them, please comment on his youtube.

[Azzy]

I have some reading to do tonight

Thanks for this post!

[Single shot]

TC,
Great write up, well worth saving so that we can easily refer to it in the future. I do have two questions at this time, I don't remember seeing any reference to these questions but I may have missed it.

You talked about firing pin protrusion :

" if you change your firing pin you MUST check the protrusion of the firing pin. I checked mine before I took it out shooting and it was sticking out WAY too far; which can result in breakage, pierced primers and a resulting potentially unsafe condition "

Can you tell us by measurement just how far a firing pin should protrude from the face of the bolt of a rifle that has tight headspace ?

Also great write up on barrels :

You wrote:
"So now that the barrel is all finished, the recoil lug is placed over the threads and the barrel is threaded into the action and checked for proper head spacing. The barrel, recoil lug, action and bolt are now sitting in perfectly alignment, stress free ( hopefully ), and making full and even contact. For all practical purposes, the rifle can be slapped in a stock and is ready to go"

My question on barrels is just how tight should a barrel be screwed on to the action ?.

Again very nice write up, a BIG Thanks for all the effort you put into this.
SS

[Tomcat088]

Originally Posted by Single shot

TC,
Great write up, well worth saving so that we can easily refer to it in the future. I do have two questions at this time, I don't remember seeing any reference to these questions but I may have missed it.

You talked about firing pin protrusion :

" if you change your firing pin you MUST check the protrusion of the firing pin. I checked mine before I took it out shooting and it was sticking out WAY too far; which can result in breakage, pierced primers and a resulting potentially unsafe condition "

Can you tell us by measurement just how far a firing pin should protrude from the face of the bolt of a rifle that has tight headspace ?

Also great write up on barrels :

You wrote:
"So now that the barrel is all finished, the recoil lug is placed over the threads and the barrel is threaded into the action and checked for proper head spacing. The barrel, recoil lug, action and bolt are now sitting in perfectly alignment, stress free ( hopefully ), and making full and even contact. For all practical purposes, the rifle can be slapped in a stock and is ready to go"

My question on barrels is just how tight should a barrel be screwed on to the action ?.

Again very nice write up, a BIG Thanks for all the effort you put into this.
SS

Howdy singleshot, thank you for the compliment on the thread, and no you did not miss a reference to the questions you asked. I do have some answers for you though. I'm not a gunsmith and I knew the answer, but I wanted to verify the information so I wasn't giving misinformation about firing pin protrusion.

This information has been verified by William of Louisiana Precision, and my buddy. Some people do debate about firing pin protrusion, especially the BR guys. There are things that will effect firing pin protrusion, and some people will adjust it for different primers that may have a slightly thicker cup, etc. Either way, the standard firing pin protrusion on a Remington 700 is between .050-.060" . That is what factory and standard Remington 700's SHOULD be between.

Now in reference to how tight the barrel should be screwed onto the action, it really does have a certain "feel" to it. As far as I know, there isn't a type of "torque" action wrench, they're just a wrench that fits in the action so you can tighten it; some people use a "barrel wrench". The action and barrel are quite tight (relatively), you should not be able to loosen one unless you have it in a vice and have the action or barrel wrench. How tight you tighten the action DOES effect the headspacing, so it is ALWAYS checked after the barrel is tightened down to where you want to leave it. It's a relative thing, you want it to be tight, but not tight enough to strip threads or put added stress in thing. Sorry that I'm not more specific, but it really does have a "feel" and the headspace still has to be correct and safe. Hope that helps, and please keep the questions coming if ya'll have any.

[Single shot]

Thanks for the Info Tom Cat, it's very helpful.
I thought for sure that there would be something more exact for getting the barrel tight other than just feel because everyone's "feel" can be different, also some say that stress can be put on a action by getting the barrel to tight.

A friend told me that some just use lock tight, that way there cant be any stress on the action, have you ever heard of anyone doing that, and how do you feel about it, sounds to simple to me, screw the barrel on hand tight, check the headspace, if everything is ok un-screw, apply lock tight screw back on hand tight, let set for 24 hours. I can see where it would be stress free but do you think it would hold ?.
SS

[Tomcat088]

Originally Posted by Single shot

Thanks for the Info Tom Cat, it's very helpful.
I thought for sure that there would be something more exact for getting the barrel tight other than just feel because everyone's "feel" can be different, also some say that stress can be put on a action by getting the barrel to tight.

A friend told me that some just use lock tight, that way there cant be any stress on the action, have you ever heard of anyone doing that, and how do you feel about it, sounds to simple to me, screw the barrel on hand tight, check the headspace, if everything is ok un-screw, apply lock tight screw back on hand tight, let set for 24 hours. I can see where it would be stress free but do you think it would hold ?.
SS

You're very welcome for the info and I'm happy that I can help. Yeah, you can induce stress on the barrel or action by tightening it too much. The stress is fairly uniform though if the threads are cut properly, because they all make equal contact and distrubute it over a good distance and equally. You don't want it "brute force tight", that's for sure, but you dang sure don't want it getting loose and moving around. There may be some way that exists, or some setups that are similar to torque wrenches, but I've never seen one, or a gunsmith make one. They usually make any tools they can't buy, or special rig, and I've never seen one. My buddy doesn't even use a torque wrench when he tightens the action screws, he can "feel" it from a T handle allen wrench. I've checked it several times with a torque wrench and it's never but maybe 1 pound off. So yes a normal person's "feel" will be different from anothers, but gunsmiths typically get pretty adept at being VERY consistent in that feel and knowing what shoots and doesn't. It's not all that common for people that aren't gunsmiths to be removing the barrel from the action, although it does happen sometimes.

I do think that the loctite method can work, although it would depend on the loctite. Screwing the action off and on isn't quite as simple as you think, usually there MUST be a release agent/anti seize used. Remember that the metals are different between the action and barrel, so they expand and contract slightly differently just in normal temperatures, but especially if the barrel has been shot, in the lathe, etc. If you don't use it, sometimes it can be dang near impossible to get the two apart. If they do get siezed, sometimes you have to heat the metal up until it's VERY hot, which is NEVER good for the action; it can weaken the action, change stress in it, or induce stress in it. Usually if you have any doubt about the integrity of the action or heat it up, people have the action magnufluxed and x-rayed (not cheap).

Contrary to what some people would think, there are some reasons that someone may want to remove a barrel from the action. There are lots of people that have custom rifles built who want "switch barrel" option. If a barrel is loctited in, this will not be practical or easy, which is part of the reason for having a switch barrel. If you loctite a barrel, it will most likely hold, but there's also a good change that you may have to heat the action later to get it off. Again, if you have to heat a barrel it can compromise the action, which is not what you want. In my experience, a competent smith will not induce stress in the action or barrel. Remember that the "easy way" is not always the "best" way, and I personally think that loctiting a barrel is a shortcut. Gunsmithing is an art, they know how to tighten it up so it won't back out, but can also be removed.

People that go to the trouble of building a custom rifle will eventually shoot out a barrel, that's the way it is. This means that at some point the barrel WILL be removed, and you want to be able to remove it without a lot of trouble (magnafluxing, xray, etc), or worrying about the integrity of the action. Switch barrel is also just something nice to have available if you would like to be able to switch calibers and have everything else the same on the rifle (sometimes change the bolt, depending on caliber). There ARE people that loctite barrels in actions, it's just my opinion that it's not ideal or the way that I would personally have it done.

[Single shot]

Thanks again Tom Cat,
Very informative.
S S

[LisaA]

This is a fascinating and educational post, Tomcat088. Thank you for providing this info. I wish I had the machine tools to do this.