243AI throating question

[johnfred1965]

I am looking to rebarrel my 243 to AI with two bullets in mind: The 87gr v-max and the 108 ELD-M. Is there a compromise throat lenght that could work with both these bullets, or should I just throat for one and take my chances with the other?

 

[alinwa]

May I note here that "throat length" is slightly more complicated than just length?? Leade configuration(s) and angle play into seting length/depth.....I have reamers cut to several different angles and some use compound angles or even stepped leades. I believe in building the entire rifle from the leade outward, both ways. I try to get the angle cut to match the ogive of the bullet of my choice. I believe this to be critical for consistent ES. And from this careful cradling of the ogive I measure back to establish "throat length."

I've been so successful at this that my biggest problem right now is that even using a silver sharpie on the bullet I'm finding it difficult to get visible land marks on my bullets! Just last week I was having trouble getting an easy reading on seating depth and finally looked in with the Hawkeye to find my entire leade angle completely silvered up with ink, and only the lightest of scuffs on the bullet's ogive....

In your case, since I'm not a "compromise" type guy, may I suggest you make a small choice..... ya got's ta' ASK yerself "which is more important, accuracy or velocity??"

If the answer is "VELOCITY!" then throat for the longer bullet and let the shorter one jump.

If the answer is ACCURACY" then throat for the shorter bullet and then the longer one will still set into the lands nicely, just hang down into your powder chamber a liddle.

Maybe this will help to get the proverbial discussion ball rolling

 

[Jesswil61]

Agree with all that alinwa has stated. I have shot out several 243ai chambered barrels and in my experience I have not had any that didn't like substantial jump however they have all been barrel burners.

 

[shortgrass]

I am looking to rebarrel my 243 to AI with two bullets in mind: The 87gr v-max and the 108 ELD-M. Is there a compromise throat lenght that could work with both these bullets, or should I just throat for one and take my chances with the other?

Are you doing the chambering yourself?

 

[johnfred1965]

May I note here that "throat length" is slightly more complicated than just length?? Leade configuration(s) and angle play into seting length/depth.....I have reamers cut to several different angles and some use compound angles or even stepped leades. I believe in building the entire rifle from the leade outward, both ways. I try to get the angle cut to match the ogive of the bullet of my choice. I believe this to be critical for consistent ES. And from this careful cradling of the ogive I measure back to establish "throat length."

I've been so successful at this that my biggest problem right now is that even using a silver sharpie on the bullet I'm finding it difficult to get visible land marks on my bullets! Just last week I was having trouble getting an easy reading on seating depth and finally looked in with the Hawkeye to find my entire leade angle completely silvered up with ink, and only the lightest of scuffs on the bullet's ogive....

In your case, since I'm not a "compromise" type guy, may I suggest you make a small choice..... ya got's ta' ASK yerself "which is more important, accuracy or velocity??"

If the answer is "VELOCITY!" then throat for the longer bullet and let the shorter one jump.

If the answer is ACCURACY" then throat for the shorter bullet and then the longer one will still set into the lands nicely, just hang down into your powder chamber a liddle.

Maybe this will help to get the proverbial discussion ball rolling

I was going for accuracy, I figured if I lost a little loading the long bullets deep, I would still be faster with the AI than my current 243. I guess I was having a brain fart, I was thinking throating long to match the long bullet for accuracy, didn't occur just to go short andget both bullets close to the lands.

 

[johnfred1965]

Agree with all that alinwa has stated. I have shot out several 243ai chambered barrels and in my experience I have not had any that didn't like substantial jump however they have all been barrel burners.

My original 243 burned up quick enough, but I loaded it mostly with 70 gr B-tips for P-dogs. It finally got to shere it would copper foul from chamber to muzzle. When I pushed a patch through, I would get copper wire out the other end!!

 

[johnfred1965]

Are you doing the chambering yourself?

I will not be chambering myself. I was either going to order a custom reamer, or find a gunsmith with a reamer that would work for me.

 

[Dusty Stevens]

a 243 and 6mm AI are 2 wicked chamberings. I have a 22/6mm rem AI and its a beautiful thing as well.

 

[urbanrifleman]

The SAMMI throat works perfectly, it ends up being about 85 thou. Or you could order a reamer at 125 thou if you are afraid of donuts. This is essentially the long match reamer number for the Dasher, which has nearly the same neck.

Just look at the Dasher and do what they do.

I do not size my entire neck, and I use the standard SAMMI 277 neck with Lapua brass unturned, so I don't get donuts.

 

[Toby Bradshaw]

Not SAMMI. Sporting Arms and Ammunition Manufacturers' Institute (SAAMI).

 

[urbanrifleman]

Not SAMMI. Sporting Arms and Ammunition Manufacturers' Institute (SAAMI).

It's the Sammy Davis spec