Custom chamber means custom loads, right?

[0311 Hesco]

Help me out here. I am putting together two .260s and it will all be custom. I have been fighting back and forth about single shot or mag-fed. My question is: when you have a smith chamber a barrel, can't you get it with a custom "jump" off the rifling so you can get your loads COAL to the size YOU want as opposed to what the GUN likes and it still be the "best" load for the gun? Seems to me there would be a formula out there for instance you cut the chamber to "X" size if you want to have the best custom load with "Y" COAL (for fitting into a magazine specifically). I understand there are a ton of other variables but is there something better than a ballpark estimate for something like this?

 

[0311 Hesco]

Maybe this should have been put in gunsmithing or reloading? Moderator?

 

[wtopace]

Chambers are cut to a specific depth to set the headspace on the rifle, that is not configurable. What you are thinking of is the throat or "leade" or "freebore". All chamber reamers have a throat dimension that you can calculate the jump distance of your bullet from. Factory barreled rifles like Remingtons have a very long freebore, which allows you seat bullets out extremely far without ever touching the lands, however, most custom chambers are cut much shorter.

When you have a smith cut a chamber, you have a few options:
1) Order a specific chamber reamer with a custom freebore to match my loaded dummy round (you can actually send the round to PTG and they will make you a reamer if you want)
2) Use the reamer the smith already has and optionally a throating reamer to increase the freebore
3) Use a 0 freebore reamer and cut the entire throat with a throating reamer (this is fairly common in the custom rifle world)

Since I chamber my own rifles, I usually choose option 1 and keep all my chambers identical for each caliber. Although it doesn't fix all variables like powder charging, it unifies your case prep to share among rifles. Hope this helps a little!

 

[WB300]

I had a 300WM built off of a Rem Sendero action. I had the chamber cut tight with a short throat so I could load from the original internal mag and not have to jump too far. I didn't bother to have it cut for a specific bullet as I didn't want to be tied to just one. I'm not too concerned about velocity as I am about accuracy. I started working with loads figuring I HAD to for the best accuracy. So far nothing beats how Black Hills 190 BTHP and Winchester Supreme 180 Accubonds shoot. Both give me about 3/4" at 200 yards. So in my experience... custom rifle does not mean custom load. (then again, my rifle is not completely custom).

Not sure if this is what you are asking. Hope this helps.

Bill

 

[0311 Hesco]

Chambers are cut to a specific depth to set the headspace on the rifle, that is not configurable. What you are thinking of is the throat or "leade" or "freebore". All chamber reamers have a throat dimension that you can calculate the jump distance of your bullet from. Factory barreled rifles like Remingtons have a very long freebore, which allows you seat bullets out extremely far without ever touching the lands, however, most custom chambers are cut much shorter.

When you have a smith cut a chamber, you have a few options:
1) Order a specific chamber reamer with a custom freebore to match my loaded dummy round (you can actually send the round to PTG and they will make you a reamer if you want)
2) Use the reamer the smith already has and optionally a throating reamer to increase the freebore
3) Use a 0 freebore reamer and cut the entire throat with a throating reamer (this is fairly common in the custom rifle world)

Since I chamber my own rifles, I usually choose option 1 and keep all my chambers identical for each caliber. Although it doesn't fix all variables like powder charging, it unifies your case prep to share among rifles. Hope this helps a little!

I guess I'll talk to the smith a little more about this. I'm essentially trying to rationalize the ability to magazine-feed the .260 so I can run it in tactical matches.

BTW, GREAT blog!

WB300:
maybe I titled it wrong. I guess it should have been: can I custom cut my chamber to fit a desired OAL. That's really where I was going I think. Thank for the help

 

[downhill]

I've went with 0311 Hesco's option 3 with "x" amount of jump to my dummy round in 4 different calibers. Had great results each time.

 

[wtopace]

I guess I'll talk to the smith a little more about this. I'm essentially trying to rationalize the ability to magazine-feed the .260 so I can run it in tactical matches.

BTW, GREAT blog!

WB300:
maybe I titled it wrong. I guess it should have been: can I custom cut my chamber to fit a desired OAL. That's really where I was going I think. Thank for the help

Glad you liked the blog, sorry it's not very up to date! Yes, you can absolutely have the freebore cut to a specific length to fit your desired OAL. Since the bullet will measure off the ogive (this also depends on the leade angle), I would recommend getting in contact with your smith to see what kind of reamer inventory he has (he may already have a 0fb reamer and a throater so you have nothing to worry about). If you have to order a custom reamer, consider Dave Kiff at PTG, give him a call and he'll take the time to talk you through your first order (he'll most likely recommend sending a few dummy rounds to him or at the very least telling him what bullet you plan on shooting and he can adjust accordingly).

Good luck in your matches!

 

[0311 Hesco]

Thanks, I have Tom Sarver from TVP doing the rifles. Surely he knows what's going on, I haven't talked specifics with him yet. I just wanted a baseline knowledge on this sort of thing first. Thanks for the help!