Gunsmithing What is the Free bore of a match Grade rifle

[Tex1970]

I am trying to learn what is considered the normal free bore for a 308 Winchester rifle with a match grade chamber? I know that the old Remington PSS's had as much as 0.090 of free bore and were hard to reach the rifling. So before I order a match barrel with a match chamber I am wondering what to expect or ask for in free bore. Thanks for any help.
Randy

 

[858]

Re: What is the Free bore of a match Grade rifle

Depends...

 

[Brain]

Re: What is the Free bore of a match Grade rifle

What's your definition of a "match grade chamber" Tex?

 

[Victor N TN]

Re: What is the Free bore of a match Grade rifle

There's only about a hundred reamers that are considered "match grade". The best way to find out is to seat a long bullet and measure it. Cast the chamber if you need something you can see.

 

[USGUNWORKS]

Re: What is the Free bore of a match Grade rifle

My chambers have been 2.840 to the lands with a 175 SMK.

 

[9sigman45]

Re: What is the Free bore of a match Grade rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 30calsniper</div><div class="ubbcode-body">My chambers have been 2.840 to the lands with a 175 SMK. </div></div>


Do you know what the "free bore" measurement of your chambers is?
Thanks!

 

[USGUNWORKS]

Re: What is the Free bore of a match Grade rifle

.040

 

[Greg Langelius *]

Re: What is the Free bore of a match Grade rifle

My approach was to specify a particular bullet when ordering the barrel, and leave it to the maker to determine the freebore. When it comes to the really technical stuff, I defer to the professionals, who already know far more about these things than I ever will. The point about going to professionals is to take advantage of their wisdom so I don't have to try and duplicate it. Their wisdom beats mine, hands down.

 

[BLAWTON]

Re: What is the Free bore of a match Grade rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tex1970</div><div class="ubbcode-body"> I am trying to learn what is considered the normal free bore for a 308 Winchester rifle with a match grade chamber? I know that the old Remington PSS's had as much as 0.090 of free bore and were hard to reach the rifling. So before I order a match barrel with a match chamber I am wondering what to expect or ask for in free bore. Thanks for any help.
Randy </div></div>

Need more info to be able to answer. What bullets are you planning on shooting? Thats the only thing that will help figure out what you need. As Victor sorta said there is tons of reamers. Freebore doesnt have much to do with it being match. That would depend more on the neck size. And you can alos just use a freebore reamer to set your own.....

 

[Keith Johns]

Re: What is the Free bore of a match Grade rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">My approach was to specify a particular bullet when ordering the barrel, and leave it to the maker to determine the freebore. When it comes to the really technical stuff, I defer to the professionals, who already know far more about these things than I ever will. The point about going to professionals is to take advantage of their wisdom so I don't have to try and duplicate it. Their wisdom beats mine, hands down. </div></div>

+1

If your having a weapon built like a 338LM, where you know what bullet you will be using due to lack of options, the barrel maker can sometimes cut the throat and free bore to match the bullet length and ogive.

 

[USSR]

Re: What is the Free bore of a match Grade rifle

You simply seat the bullet you intend to use to the depth you want in an empty but FL sized case, send it to your smith and tell him to cut the chamber so the ogive doesn't quite touch the leade.

Don

 

[palma]

Re: What is the Free bore of a match Grade rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">My approach was to specify a particular bullet when ordering the barrel, and leave it to the maker to determine the freebore. When it comes to the really technical stuff, I defer to the professionals, who already know far more about these things than I ever will. The point about going to professionals is to take advantage of their wisdom so I don't have to try and duplicate it. Their wisdom beats mine, hands down. </div></div>

I'm far from a tech guy, but based on a bad experience, I don't defer to the builder. COAL is a matter of opinion, and opinions vary widely among smiths. One smith, for example, may believe it entirely appropriate to give up some powder capacity just to run a long bullet at mag length. I always provide loaded ammo with the instruction, for example, to throat the thing so that the bullet touches the lands. Loaded ammo is the way to go.

 

[9sigman45]

Re: What is the Free bore of a match Grade rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: palma</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">My approach was to specify a particular bullet when ordering the barrel, and leave it to the maker to determine the freebore. When it comes to the really technical stuff, I defer to the professionals, who already know far more about these things than I ever will. The point about going to professionals is to take advantage of their wisdom so I don't have to try and duplicate it. Their wisdom beats mine, hands down. </div></div>

I'm far from a tech guy, but based on a bad experience, I don't defer to the builder. COAL is a matter of opinion, and opinions vary widely among smiths. One smith, for example, may believe it entirely appropriate to give up some powder capacity just to run a long bullet at mag length. I always provide loaded ammo with the instruction, for example, to throat the thing so that the bullet touches the lands. Loaded ammo is the way to go. </div></div>


I agree! Plus, what's wrong with wanting to learn?

I have a build in the works right now that I have specified will be used strickly for F(tr) class matches. I also notified the builder (well thought of here on the hide) that I have NIB Lapua brass (I bought a case 1,000) that will only be used for this rifle. I also made it known that I plan to use 175gr and/or 190gr SMK bullets. The reamer specs I was provided (after specifically asking for them) was ".342 jk 90fb 1 deg 30". Now that I see 30calsniper saying that his chamber has a 0.040" free bore and uses 175gr SMK, I'm second guessing my builder's sugestion. What say you more knowledegable hide members; am I OK or should I ask for something different? Maybe 30calsniper needs the shorter free bore because he loads to mag lenght, where I'll be single loading. Dunno?

I'm afraid that my technical ingnorance with custom rifles has begun to frustrate the builder, so I'm leary about questioning their suggestion. I wouldn't think that it should be a problem, because as far as I know, nothing other than a barrel order being placed has been done at this point. But it's kind of like complaining about your food at a resturant and sending if back to the kitchen. I never do that ;>).

 

[Greg Langelius *]

Re: What is the Free bore of a match Grade rifle

We have no disagreement.

Learning is good, and yes, there are folks who don't know their apples out there. When I was referring to the professionals, I meant my my barrels are made and chambered by L-W. I think I have a better then even chance of getting a good result from their likes.

As for learning, subjects like cutting a chamber and leade are lessons I doubt I'll really have much use for; but yes, it's interesting data for future reference.

Greg

 

[Tex1970]

Re: What is the Free bore of a match Grade rifle

Thanks gentlemen for all the help, I am wondering, because I have a FN SPR A5M with 0.035 free bore with 168's and even less with the 175, then I have a Kimber tactical with 0.040 for 168's and again less for the 175's. Now why state all this, because I have a build rife just about done and am curious what to expect from this new rifle considering it was reamed with a match grade 308 reamer which I equate with tighter tolerances such as found at the low end ot the SAMI specs for the 308, like the National Match 308. You have all given me something to think about and like alot of you I leave the specifics to the professionals, knowing it will be able to fire 168-200 makes it mandatory to have some free bore unless as mentioned above you are planning on only shooting one bullet. Thanks again and I will fill you in soon I hope it's a TBA rifle. Thanks again

 

[jetlyting]

Re: What is the Free bore of a match Grade rifle

The best way to do this is to call Dave Kiff and Pacific gauge and tool and talk to him about the exact bullet you plan to shoot. You can then spec out the finish reamer exactly the way you want it for your match barrel and send it with the barrel to your smith. He will explain all the ins and outs pros and cons so even I could understand it. He will also tell you what guys are winning with right now with caliber and bullets. Once you have your own reamer you can get 6-10 barrels out of it and even use it to make you some custom reloading dies. I took a match barrel gunsmithing class in Iowa with gunsmith Gordy Gritters and really learned from the best how to barrel a match gun and make my own dies. He really knows his stuff and is one of the leading gunsmiths as far as taking home first place trophies. hope that helps