6mm rem AI for compitition?

[40X Guy]

Hey folks! Called Manson Reamers the other day and got the specs. on their .244 Rem. A.I. reamer. I hope I am not out of line for posting this. Their reamer has .100" freebore, a 2.5 degree leade, and a .277" neck. This reamer can be obtained with a solid or live pilot. I am thinking this reamer would probably do for a varmint rig with the lighter pills. Can't lie though, would like a little shorter throat and a 1.5 degree leade. The leade angle as recommended by a member earlier in this thread but, I imagine it will work. What do you folks think? Thanks!

Mike

If you opt for that reamer, buy some Norma 7X57 brass and go thru the trouble of necking it down to fit that .277 chamber better, my first 6AI has a .278 neck and Winchester brass loaded miked at .269, just a little loose, my 7X57 brass after being necked down in 2 stages and expanded measures .2745-.275 loaded. Its perfect for my rifle, but brass in the neck is kinda thick, so I am looking at annealing this brass before the season starts.

My newest 6AI sports a .269 neck and I will be going back to Winchester brass on that one and the required neck turning to make them work.

Frank

 

[bozo699]

Frank,
I have two reamers for 6AI but not sure of n/k size, what size do you think it would need to be for win brass with a no turn in mind and what size for win brass just cleaned up. I guess I could do some measuring instead of asking you silly questions.
Wayne.

 

[CanusLatransSnpr]

Say I opt for this reamer, I have two questions reguarding this choice. According to my Lymann reloading manual, the 6mm rem. has a .276" neck. Now if I were to use Winchester brass, couldn't I just neck size it to .274" neck, then loaded diameter giving me a .276" neck, affording me a .0005" clearance around the entire neck of a chambered round? The next question is for the Norma 7x57 brass. If I were using Redding Type S dies with the bushings, couldn't I just buy the proper bushings to neck down the 7x57 brass in a couple of steps? Or would I have to purchase a die 6.5mm family for the initial neck down? Just some thoughts! Thanks!

Mike

 

[40X Guy]

Frank,
I have two reamers for 6AI but not sure of n/k size, what size do you think it would need to be for win brass with a no turn in mind and what size for win brass just cleaned up. I guess I could do some measuring instead of asking you silly questions.
Wayne.

Wayne, for a no turn neck somewhere around .271-.273 depending on lot of brass, this newest lot I just bought is about .001 larger neck than the old lot of brass I bought a year ago.

Frank

 

[40X Guy]

Say I opt for this reamer, I have two questions reguarding this choice. According to my Lymann reloading manual, the 6mm rem. has a .276" neck. Now if I were to use Winchester brass, couldn't I just neck size it to .274" neck, then loaded diameter giving me a .276" neck, affording me a .0005" clearance around the entire neck of a chambered round? The next question is for the Norma 7x57 brass. If I were using Redding Type S dies with the bushings, couldn't I just buy the proper bushings to neck down the 7x57 brass in a couple of steps? Or would I have to purchase a die 6.5mm family for the initial neck down? Just some thoughts! Thanks!

Mike

Mike, answer to question one is that new 6MM Win. brass is around .268-270 new neck diameter, so you would not be able to neck size with the .274 bushing before or after as there will not be anything to grip bullet because the neck wall thickness stays the same., and as to necking down the 7X57 brass, you need FL dies to do the job in 2 steps, as the entire neck needs to be necked down and keeping the shoulder where it needs to be. Also plenty of Imperial lube for the cases. I used a .257 Roberts and a 6MM standard FL RCBS die with the expander ball removed, then used my Sinclair 6MM expander mandrel to expand inside of neck back to .243. Depending on your chamber you may have to neck turn or in my case they were perfect after going thru the 3 step process, also the Norma brass is very consistant. Hope this helps. If you decide to go with the Norma brass, send it to me and I will size it down for you, you pay shipping and buy a beer. ;D

Frank

 

[Elwood]

I have to agree with 40X, if you're thinking of using Norma or RWS brass then think about a larger neck diametre. My chamber is a .273 and I had to turn RWS brass down 11 thou to get a case neck of .271 loaded.

Winchester on the other hand measures .270 loaded with just a 75% neck clean up.

I would also agree with using the .257 Roberts die, I did manage it using a .243 FL die with the expander removed and then through a 6mm Rem FL die but it really works the brass.

I fire formed with cream of wheat and found it to be easy and cheap.

From right to left are RWS 7x57, after running it through a .243 FL die, then a 6mm Rem and the final case fire formed and loaded. And for those of you with good observation this is a 6mm Crusader and not the 6mm AI.

 

[CanusLatransSnpr]

Frank, thankyou for the insight! I was afraid that it would take multiple dies to neck down the Norma 7x57 brass! Like you said, Norma brass is very good. Everything I've read claims that brass is the way to go for a 6mm rem. A.I. It will last a long time too. If I were to use the 6mm Win. brass, it looks like I should shop around for a reamer with a little tighter neck. Your offer to size all the brass for shipping and a beer sounds like a good one ! Maybe you could start up a little business there to keep stocked in beverages ! Thanks again!

Elwood, thanks for the +1 on working the brass! Looks like I have some decision making to do!

Mike

 

[40X Guy]

Mike, let us know what you decide.

Frank

 

[CanusLatransSnpr]

Will do Frank! Thanks again for the input !

Mike