tp555 300 whisper barrels
 

Hello, I'm thinking of getting one of tp555's 300 whisper barrels. I would like to hear from anyone who has one.

How's accuracy at subsonic speeds?

Special tips and load data? I want to use heavy subsonic projectiles with a suppressor.

thanks,
swampf0x

Can't help now, but give me a few months and I'll be doing exactly that. I decided to build a dedicated subsonic gun and shoot only 240 SMK, but I did get his 3way block for options.

This is a slow forum, but maybe someone will help us both out on the learning curve. :)

I still have one he built for me from a stainless Brux blank I sent him a long time ago....shoots subs very,very nicely.
I dont think anyone has any worries dealing with TP555, the guy knows his stuff.

I have been very pleased with my barrel and 3-way gas block. I�m still working up loads so I don�t know the ultimate accuracy potential but I am happy with the results so far.

His response to emails and questions were always prompt and helpful.

If you order one of his gas blocks I would recommend ordering a gas tube from him as well. The adjustable gas block requires a gas tube a little shorter (5.75� OAL IIRC) than a standard pistol length gas tube. It is a PITA to shorten and bend a pistol length gas tube (at least it was for me and I didn't have the tools to properly flare the end).

and a case guage! I've been very happy with his CS and willingness to answer newb questions. From the name of the company he is a machinist first and gunsmith second. Machinist are by nature perfectionists, gunsmiths not so much.

He said he would assemble my upper for me for a modest $20

Why do I need a case guage? What is a case guage?

swampf0x

Have you reloaded other catridges before?

It is a gauge that tells you how to set your resizing dies so they resize the case enough but not excessively which will shorten your case life.

Usually these are based on SAAMI specs and are general.

For 300 Whisper or other custom barrels, you can have the smith cut you a gauge which is actually bored with the same reamer that your barrel is cut with.

This is more of a chamber gauge which is a perfect match for your barrel and almost a necessity when initially forming 300 Whisper brass and resizing after fire forming.

A custom chamber gauge may also have the beginning of your rifling so you can set the OAL of your reloaded rounds to be jammed in the throat, a small distance from the throat, or have a slight jump.

In an AR you will be limited by the magazine length for the OAL so some barrels have a shorter throat which can be a good or bad thing depending on if you are aware of it and know how to utilize it.

Case gages are very useful.I bought another 30/221 reamer from PTG.The Clymer reamer is based on the 1.4" OAL case.The PTG is based on the 1.35" OAL case.Longer case won't work in the shorter chamber.Most first time brass forming is from once fired brass.Mil brass is thicker and tougher.The problem is usually the shoulder neck area.The case has a very short shoulder but the forming leaves a radius here.It hits and causes problems.Once fired its good.The Redding dies need a good bottoming out to work on a Dillon press.So If the round drops into the gage it will work. Mil brass had neck separation after 5 reloadings for me.I would anneal the neck area after cutting to 1.4".This is a lot of work.One guy bought a barrel from me and had Teppo Jutsu build the upper.It wouldn't fire the ammo he bought from someone else.He was unhappy.Trash the upper after much $ or trash the ammo.Don't know how it turned out.

I've reloaded other catridges but I've never used a case gage. I just load to the recommended OAL and let it be.

Once I shoot up all my 223's I plan to let someone form my brass to 300 whisper. From there I'll load my own according to info I find on this site.

If tp555 builds my barrel and assembles my upper (and he probably will) Who should I get to form/size my brass so that I won't have any problems?

thanks,
swampf0x

For accuracy you need to know where your Datum is in relation to the bore.

There is too much to it for me to explain in print and I'm new to accuracy loading myself, but I can suggest a great book on the subject.

http://www.amazon.com/Handloading-Co.../dp/096269259X