25 CM AR10?

Has anyone here built 1? I am contemplating what to build with an AR10 lower. I am a quarter bore fan, so a 25CM seems like an interesting option.

Do you like your build, are there better options?

My other thought for the build is 180* the other direction and to build a 12" 308 pistol!

talk with a barrel maker as for a best gas port size AND location is very important! +2 or 3 isn't necessary if port is sized proper! on some of the smaller bores they go +3 (might be a good suggestion). go with a 1/2 to a 1 full twist faster than minimum in an ar as velocities can be slower than with ba's. also, make sure you get a mag that works with the lower (reference: aero lowers don't work with acs mags due to bolt issues). the acs mags are lower cost and give a 2.860-2.870" cartridge length. on the higher end larue gives the same lengths, but cost is near $100/per. from custom makers i bought from do the gas port for adjustables in the .095-1.00" range. you can get a port reamed to what you want? i have a 243win rifle length gas that overgassed along with several other 6.5creeds. the only 2 creeds that run w/o adjustable blocks came from aero precision.

Did the same with a 27 CM but I AI'd the case so I wouldn't get them confused with the 6.5CM cases.

Zen Archery said:

Did the same with a 27 CM but I AI'd the case so I wouldn't get them confused with the 6.5CM cases.

Click to expand...

what weights were you using or wanted to use?

hey @Zen Archery, where in Texas are you? i have lots of traveling to do in most of the state for equipment replacement from the fire back in march. might be next year on the traveling before i get the money from the people responsible of the starting of it?

I'm a 1/4 bore fan. I had ER Shaw make me a 257 roberts AI for a rifle. ARlife4me stated that the max magazine COL was @2.860-2.870" According to Hodgdon reloading my max length for the rob AI is 2.885. No problem on making less COL when they make the chamber with less freebore.

The Rob AI holds about 12 more grains of powder that the 25 CM. The parent case of the 257 roberts is the 7 mm Mauser. You can buy 7mm Mausers for reletivley cheap and run them through the resizer which I do. The gain in powder adds like 300+ fps on any gr. .257 pill.

Just another option which would be the easiest is a 25-08. Use the 308 BCG. All 308 mag pul mags would work because you are using a ar10 lower. No problem with COL and the ability to put in slightly over 50 gr. of powder.

High powdered 1/4 bores just take out my local mule deer

ooohhh... I like this idea. XCaliber will make a barrel as well.

25/08 hadn't crossed my mind, but is a good thought too. Probably is more of the easy button with mags and such I bet.

I like the fact though that you can get factory stamp SRP 25CM brass.

if you find 25creed cases, then there are no feeding issues as it's the same as the other creed cartridges. neck up or down from other creed cartridges if necessary? want more power then go 6rem and neck up.

I was bitten by the 1/4 bug last year. I really wanted a 257 Roberts but the prices people were asking are ridiculous.
And the fact I couldn't find any brass or ammo for it or 7 Mauser brass either I decided to build a 25 creed.
With the 133 Berger bullets with a 22" barrel I'm getting around 2750 fps.
It's a fun caliber to shoot but after seeing the affect on chilli
Cans @ 500 yards, for hunting I think I would like a bit more speed. Haven't shot any game with it I'm sure it would do just fine on mule deer. If I were to do it again I think I would do the 25 Souper / 25-08
But I don't think I'll ever choose it over my 270 win going 3100 fps with 130 gr ttsx or accubonds. I know your talking Ar's I just prefer bolt actions for hunting.