Starting to plan a custom build thinking 6.5mm calibre

For your needs/wants the 260AI is a very good choice. I am comfortable hunting deer sized game a little farther than what you are looking for and targets are no problem much farther. Even out of a stock Rem short action mag with a COL of 2.82" I can get the speeds you are looking for using H4350 out of a 24" barrel. Accuracy has been great in almost any bullet I've fed it.
 
I am in the process of developing a 6.5-300 RCM which is essentially a 6.5 Rem mag without the belt. The 2.09" case length gives a 0.08" advantage over both the 6.5 RM and the 6.5-284 when loaded in a Short Action. The 0.265" neck and 30 degree shoulder are optimal for this cartridge.

The Hornady brass is very good with 100% being +/-1 grain of the 224.8 grain average weight. A slight neck turn, to 0.016", nearly cleans the necks up leaving a 0.296" neck diameter with bullet. I had Pacific Tool make me a reamer with a 0.301" neck diameter which allows for "no turn' or 0.005" clearance with necks turned. The reamer is cut to allow minimal case clearance and throated to allow the 140 Berger VLD to be seated near the lands with all of the bearing surface ahead of the neck/shoulder junction. This leaves a COL of about 3.04" which requires a long magnum action for the round to fit in the magazine or hand feeding in a short magnum action. I have not tried other bullets but Nosler Accubonds may fit in short action magazine when seated 0.030" back from the lands.

I am having Hornady Custom Dies made that will form new brass to minimal size and FL size brass back to new brass dimensions. This will eliminate the need to fire-form and allow the same load with fired brass as with new brass. As the chamber is cut with minimal clearance I expect no more than 0.001" case stretch per firing. Neck Sizing is an option but may not have any real advantage. I have a 20 caliber, called the 20 EXTREME, that I designed this way and it is awesome.

I have purchased a Rem 700, 300 Win Mag, with clip and B&C Medalist stock. The dummy rounds feed great from the clip but may be a bit tight with 3 and 1 in the chamber. Rounds feed good in Remington LA & SA Magnum actions but don't fare well in Winchester actions with push feed. Rounds will feed well in any action with single stack Magnum Length clips.

I have ordered a Kreiger, #5 Bull sporter barrel, 1-8 twist with 5R rifling. This barrel should fit nicely in the stock with minimal fitting. I will stick to a 26" barrel length which should be optimal for the 140 grain bullets with RL 22 at 95% case fill or slower powders like H1000, IMR 7828 and VV N165 with near 100% case fill. I expect to easily get 3200fps with the 140 VLD and one of these powders will surely shoot tight groups. I know a fellow that gets 1/3 MOA groups with RL 22 pushing the 140 VLD at 3240fps with his 26" barreled 6.5 Rem Mag in a long action rifle. His father in law is struggling to get good groups, without blowing primers, at 3100fps with his 6.5-300WSM. Imagine that with 10 grains more powder space????

If you are interested in going with the 6.5 RCM I would be happy to help you put one together. looks like you already have chosen the right barrel.

Laverne
 
I think 260AI is the way to go for me as it will be fitting into more of the type of shooting I do. I will be shooting 400-800yds more often than 1000yds in my area as it is hard to find 1000yd places to shoot.

Plus I ultimately plan to eventually rechamber the rifle to .308 when things finally get burnt out with the 260AI.

I'm just in the process of placing an order for a Stiller Tac30 action.
 
.260AI feeding

FYI, I have ATRS bottom metal now installed on my .260AI, and it will feed 5 rounds no problem.....

I'm shooting 139gr scenars at the moment, seems to be bullet of choice for this rifle at least...
 
I am in the process of developing a 6.5-300 RCM which is essentially a 6.5 Rem mag without the belt. The 2.09" case length gives a 0.08" advantage over both the 6.5 RM and the 6.5-284 when loaded in a Short Action. The 0.265" neck and 30 degree shoulder are optimal for this cartridge.

The Hornady brass is very good with 100% being +/-1 grain of the 224.8 grain average weight. A slight neck turn, to 0.016", nearly cleans the necks up leaving a 0.296" neck diameter with bullet. I had Pacific Tool make me a reamer with a 0.301" neck diameter which allows for "no turn' or 0.005" clearance with necks turned. The reamer is cut to allow minimal case clearance and throated to allow the 140 Berger VLD to be seated near the lands with all of the bearing surface ahead of the neck/shoulder junction. This leaves a COL of about 3.04" which requires a long magnum action for the round to fit in the magazine or hand feeding in a short magnum action. I have not tried other bullets but Nosler Accubonds may fit in short action magazine when seated 0.030" back from the lands.



I am having Hornady Custom Dies made that will form new brass to minimal size and FL size brass back to new brass dimensions. This will eliminate the need to fire-form and allow the same load with fired brass as with new brass. As the chamber is cut with minimal clearance I expect no more than 0.001" case stretch per firing. Neck Sizing is an option but may not have any real advantage. I have a 20 caliber, called the 20 EXTREME, that I designed this way and it is awesome.

I have purchased a Rem 700, 300 Win Mag, with clip and B&C Medalist stock. The dummy rounds feed great from the clip but may be a bit tight with 3 and 1 in the chamber. Rounds feed good in Remington LA & SA Magnum actions but don't fare well in Winchester actions with push feed. Rounds will feed well in any action with single stack Magnum Length clips.

I have ordered a Kreiger, #5 Bull sporter barrel, 1-8 twist with 5R rifling. This barrel should fit nicely in the stock with minimal fitting. I will stick to a 26" barrel length which should be optimal for the 140 grain bullets with RL 22 at 95% case fill or slower powders like H1000, IMR 7828 and VV N165 with near 100% case fill. I expect to easily get 3200fps with the 140 VLD and one of these powders will surely shoot tight groups. I know a fellow that gets 1/3 MOA groups with RL 22 pushing the 140 VLD at 3240fps with his 26" barreled 6.5 Rem Mag in a long action rifle. His father in law is struggling to get good groups, without blowing primers, at 3100fps with his 6.5-300WSM. Imagine that with 10 grains more powder space????

If you are interested in going with the 6.5 RCM I would be happy to help you put one together. looks like you already have chosen the right barrel.

Laverne

Laverne...
wow, is this scary! I was just mentioning on another board about how I would like to see just such a beauty. I am REALLY interested. Would you keep me posted with how things go? Sure would appreciate it.
I read about the 9.3 on the RCM case, and it sounds great.

Later....
 
Well I just placed an order with obtunded for a 6.5mm 5R Krieger Barrel so there is one part out of the way.

Now I have to start thinking of an action and stock. I'm going to go with a 6.5x284 round which gives me an option for Short Action actions. I'm thinking of something with a 700 footprint.

Barnard S repeater if you want a feed rifle. Barnard S Single shot if not. :)
 
Personally, if mag feeding was needed and I wanted decent mag capacity, I would go with the 6.5-06. It is every bit as accurate as a 6.5-284 in the type of rig you are describing and will offer a bit more case capacity so speeds will be the same if not faster.

Jerry, I am fairly sure the case capacity of a 6.5-284 is more than the 6.5-06, unless you went to a 6.5-06AI. :nest:
 
Just one more option that you may want to consider is the 6.5x55AI. It will chase the 6.5-284, and use less powder in the process. I have one and it feeds well, shoots very well, and is, all in all a great chambering. Regards, Eagleye.
 
Jerry, I am fairly sure the case capacity of a 6.5-284 is more than the 6.5-06, unless you went to a 6.5-06AI. :nest:

DW; The 6.5-06 standard case and the 6.5-284 case have capacities that are so close that it is hard to call. But [big but], if you chamber the 6.5-284 in a short action, those long VLD bullets are going to steal some case capacity, so in effect, it will have less than the 6.5-06. Regards, Eagleye.
 
I understand that brass case capacities can vary substantially from brand to brand and from lot# to lot#, I just thought it would be fun to :nest: :eek: As much as I love the 30-06 and its wildcats, I just think the 6.5 -284 case is so damn ###y!!!
 
Back
Top Bottom