Yes.

1.355 in a 1.350 chamber would be very bad, very bad. :)

.050 back from the actual chamber length is a good rule of thumb from what I'm reading.

If your chamber is longer you get a bit of unsupported neck which can affect accuracy (not consistently indexed) but for an AR and the expected accuracy from it, I don't believe it outweighs the potential for high pressures that will develop when your casings grow (flow rates change with # of reloads even if you trim every time) and then have no place to go in the chamber that is too short, locking the bullet in and raising the pressure to unsafe levels.

The SSK 1.350 chamber is mostly because .221 Fireball brass does not resize past 1.355 well. Shorter chamber means you can cut the case shorter, not that the OAL will change much as the magazine is the limiting factor and bullet setback is not an issue with a low pressure round like the 300 Whisper.

Since I'll be using .223 brass the 1.400 makes more sense to me.

Now, all that is just my WAG. I've yet to read anyone that says one way or another and there does seem to be a lot of guess work on this Wildcat so I'll stick with a safer 1.400 since I like the extra wiggle room it gives me and don't think accuracy is going to suffer to a point I can see it in my AR15 SBR setup.

If any of the experienced guys read this, please point out my errors in thinking!

See the thing that confuses me is I have never heard of anyone trimming below 1.35" which leads me to think that the reamer measurements are not exactly matched to the case OAL like we are assuming.

A touch too short isnt a big deal. Anything from 1.340-1.400 in a 1.400 chamber is fine.

We arent shooting benchrest here.

Yeah, I came to the conclusion that it would not matter and was reading too much BR info. Those guys are plain nuts! :grin:

Ok, I need a tp555 barrel with a 1.4" chamber?

I need to send my once fired 223 brass and 300 whisper case gage to Hoser and have him form and trim it to 1.355

When I get my brass back, I am good to load em' up? Only need to full length size them for the second re-loadings?

Now...............If I SBR it, how short can the barrel be, without interfering with the gas system and leaving enough barrel in front of the gas system to thread it for a suppressor? I think I'm gonna go with a 9mm pistol can. If I want to shoot supersonic rounds I have plenty of other rifles for that.

swampf0x

Just load them and go.

The shoulder is bumped back just fine and the base is completely resized.

I am guessing that you can get down to somewhere around 6-7" to physically allow room for threading with a pistol port gas block in place but do you really want to go that short?

I know there was a recent debate of why go with a 10-10.5" when shooting only subsonic loads with what is essentially a pistol cartridge but I think the shortest length discussed was maybe 8".

I'll try to find it.

Would there be any drawbacks to using a 8" barrel? What is the best length for a 300 whisper and why?

swampf0x

tp555 told me 9" was OK for a heavy suppressed only setup like I'm building. I believe you are looking for the same, but mentioned trying supersonics. 10.5" is the best for both.

I would not go the extra 1" shorter, although I think he did say he had made one 8" in a post here but never heard how it tunred out.

More than likely I'll be shooting subs almost all the time. But IF I ever have to grab my rifle and run, I would like to have a few mags loaded with supersonic ammo to use on bad guys

swampf0x