A little pressure is worth it?

[Rando]

7/16/09
Greetings Fellow Long Range Hunters,
I own a Model 700 300 UM and love it. As a beginner hand loader, I've spent the last year selecting the best powder, bullet, load mix and seating depth. With 94g Retumbo, and 180 Scirocco II, I'm shooting tight groups at 200 yards and hitting the gong consistently at 500 yards, 3200+ fps…perfect! Then I was horrified to discover the overall cartridges are too long! I can't fit them in my magazine. I spent another few months with the same bullets and powder, and now the overall length is simply as long as I can allow and still get the cartridges in the magazine (real scientific!). Now the bullet is much deeper in the brass, and I'm showing slight pressure signs. At 89 g Retumbo, now my groups are embarrassingly large and I'm at 2950fps. I'm inclined to accept the higher pressure and go with it, but will this damage the rifle? Suggestions?
Rando

 

[LongBomber]

Take a look at a wyatt extened magazine box. That should allow you to use your longer handloads and still fit them in the magazine well. Install requires a smith, but it sounds like it would be worth it for you.

 

[J E Custom]

7/16/09
Greetings Fellow Long Range Hunters,
I own a Model 700 300 UM and love it. As a beginner hand loader, I've spent the last year selecting the best powder, bullet, load mix and seating depth. With 94g Retumbo, and 180 Scirocco II, I'm shooting tight groups at 200 yards and hitting the gong consistently at 500 yards, 3200+ fps…perfect! Then I was horrified to discover the overall cartridges are too long! I can't fit them in my magazine. I spent another few months with the same bullets and powder, and now the overall length is simply as long as I can allow and still get the cartridges in the magazine (real scientific!). Now the bullet is much deeper in the brass, and I'm showing slight pressure signs. At 89 g Retumbo, now my groups are embarrassingly large and I'm at 2950fps. I'm inclined to accept the higher pressure and go with it, but will this damage the rifle? Suggestions?
Rando

I would recomend going to powder that has a little faster burn rate . Retumbo is one of the
powders that I have had do the same thing. (When you crowd it the pressure goes up fast)

It is good stuff and this phenomenon is not unusual with other powders.

H1000 or H4831sc and Re 22 would work and would not be as sensitive at max loads.

I think H1000 is the favorite but I like H 4831sc in mine and it produces well over 3200
Ft/sec with a 180gr bullet @ magazine length

J E CUSTOM

 

[AJ Peacock]

My number 1 concern is always accuracy. I'd keep my longer load for use at long range if I couldn't find a shorter load that shot as well. I might find a shorter load that shot 'ok', but even if I had to use a rifle single shot, I'd use the most accurate load.

The Wyatt extended mag box is a great idea if it will resolve your issue.

Also, if your load will not fit in the magazine, will it fit as the top round (in other words will it fit and make your rifle a 2 shot rifle? As the top one in a BDL/ADL can be a little longer because of the cut out at the top by the ramp. This way, you could have one in the chamber and one in the magazine.

AJ

 

[MontanaRifleman]

You might try some other bullets as well. A lot of guys seem to like 200 gr AB's on top of about 95 gr of Retumbo. I have loaded up some 180 E-Tips, 200 AB's and 210 Bergers with Retumbo and H1000 for some load development. The E-Tips and AB's I have seated to a COAL of 3.69 which just barely fit into the mag of my 300 RUM Sendero. 98 gr is about a 100% load with the E-Tips and AB's. The E-Tips are about the same length as the AB's. You could also try 180 AB's.

I agree with looking at a Wyatt's box. I may get one myself.

Hope you get it worked out. Let us know how it goes. I'm interested in the results you get.

-MR

 

[LRHWAL]

It seems you are out of the velocity node. You will need to find another lower down where accuracy returns.

In my experience SD's open up unacceptably as I get over what is the acceptable max load in my rifles. You haven't commented on SD's, but maybe that's why accuracy is poor?

If it were me I'd shoot it as a single shot. I do that anyway and find it's fine for any hunting conditions beyond 150 yards.

The longer mag box idea is a good one.

 

[trueblue]

Shoot it as a single shot, it only takes one good shot,and also get yourself a Wyatt magbox. Not to difficult to install them. Stay with your accurate load.