Great Range trip today with 300 RUM 200 AB

[SJB358]

Don,
Did you notice any difference in the barrel heat generated between the retumbo and the re-25?
just wondering, had an aquaintance that says he burnt up 3 barrels in the rum shooting retumbo, which according to the round counts he stated just seemed premature to me. I know H-1000 burns much hotter than double based powders. just curious. Great shooting BTW
RR

Are you saying RL25 burns cooler than Retumbo RR? Just wondering as I thought I experienced this when comparing the two in my 264? Probably in my head. Three shots from Retumbo will have a very warm barrel, whereas RL25 seemed a little less.. Again, maybe in my head or I misunderstood you..

 

[Ridge_Runner]

Don,
Did you notice any difference in the barrel heat generated between the retumbo and the re-25?
just wondering, had an aquaintance that says he burnt up 3 barrels in the rum shooting retumbo, which according to the round counts he stated just seemed premature to me. I know H-1000 burns much hotter than double based powders. just curious. Great shooting BTW
RR

Are you saying RL25 burns cooler than Retumbo RR? Just wondering as I thought I experienced this when comparing the two in my 264? Probably in my head. Three shots from Retumbo will have a very warm barrel, whereas RL25 seemed a little less.. Again, maybe in my head or I misunderstood you..

Scotty, In my experience, double based powders have a way less burn temp than single base, just looking for more info to try to connect the barrel life/vs burn temp comparison that I have saw.
no doubt you've heard this but, whn kirby did my 7mm AM , he told me to try an experiment, load up a top level load with a single base powder and shoot three rounds, check the barrel heat, then use a top level ball powder and do the same, the viable candidate was my stw, I fired 3 rounds of 140 gr NBT's loaded to 3550 fps with H-1000, barrel was very hot to the touch, then I fired 3 rounds with 160 AB's loaded to 3340 fps with WC872 (couldn't hit top level with a 140 with 872 in that case) the barrel was just warm. thats why in my big cases I deal with the temp sensativity in the hopes of extending barrel life.
RR

 

[SJB358]

Makes sense to me RR. Still learning from you all..

 

[Guest]

Just got back from the range. Following are the results. I found at the 95.0 Retumbo load level no matter what the seat depth it still somewhat wipes the case heads, extracted with some resistance. Seating the bullet deeper resulted in the groups opening up on all accounts. I loaded 94.5 Retumbo at the initial seating depth which is length of magazine, group was not so good and it still wiped the case head.

Going to keep dropping the charge level to eliminate the pressure issue then go from there later.

The good news here is it's looking more like RL25 will be the powder. I increased the RL25 powder charge from 91.5 to 92.0 keeping the original seating depth. I shot a three shot .817 group with 3081 fps average, 18 ES. Standard Deviation was 9.0, No signs of pressure.

I did pay particular attention to Barrel heat levels using Retumbo and RL25. I can say there was nothing significant to note but Retumbo seemed a little warmer, not by much though. Range Temp. today was 62-degrees F.

Don

 

[DrMike]

It does sound as if RL25 is your powder. That isn't a bad group; you can work with that.

 

[Guest]

Dr. Mike,
I agree. The gun responses very well with RL25. I was trying to achieve 3100 fps but will be content where it is. The accuracy is there and I can use my re-sized brass. That 200 AB sure has made a difference at least in my rifle.

I promise I will post pictures for everyone soon as I can.

Don

 

[DrMike]

Don,

You are within spitting distance of 3100 fps. The accuracy is very good, however, which more than compensates for the 20 fps differential.

 

[Guest]

Dr. Mike,
I agree. I was just pouring over all my data from last week and today. Using the JB Ballistic Calculation program I'm where I want to be. I was comparing the 180 @ 3300 fps against the 200 @ 3081 fps. The 200 clearly gives the edge at 400-500 yds. I like the energy the 200 offers translating to a bigger hammer on game plus the added weight retention. My ES and SD are there with RL25. My conclusion after reviewing all the results is to go with RL25 and stop messing around with Retumbo.

Don

 

[DrMike]

That load is for sure a hammer! Great results for your4 work.

 

[Guest]

Thank you Dr Mike. It's very satisfying once you achieve good results after all the work.
I appreciate all your input over that time period too.

Don

 

[SJB358]

Don't that 200 at 3100 won't likely be stopped by much! What a combo for Western hunting.

 

[Guest]

Yep, I got the Hammer now. Gonna verify the grouping again with RL25 then move on to some Long Range Shooting. That has always been my goal in this process. :mrgreen:

Don

 

[SJB358]

Yep, I got the Hammer now. Gonna verify the grouping again with RL25 then move on to some Long Range Shooting. That has always been my goal in this process. :mrgreen:

Don

I think you'll be in great shape Don. What set up are you running?

 

[Guest]

I've been using the DF Lead Sled lately for load development. Going to switch to Bench rest and bags next trip. I shot that really good group posted months back using 180 AB that was .442 off the Bench Rest and Bags. For Long Range so far I like my Harris Bi-Pod and Bags shooting Prone, but I need to explore other shooting positions as you can't always get into prone when shot opportunities are present.

What's your set up?

Don

 

[SJB358]

I've been using the DF Lead Sled lately for load development. Going to switch to Bench rest and bags next trip. I shot that really good group posted months back using 180 AB that was .442 off the Bench Rest and Bags. For Long Range so far I like my Harris Bi-Pod and Bags shooting Prone, but I need to explore other shooting positions as you can't always get into prone when shot opportunities are present.

What's your set up?

Don

I was actually talking about your rifle and such. I use bags for the bench then either billed or my ruck for the field.

 

[Guest]

Just found out some good news tonight from a Hunting Club Member here where I belong. There is an area within the 800 acres we hunt to shoot over 300 yards. Now I am excited. He's going to show me the area in 2 weeks.

Don

 

[JD338]

Just found out some good news tonight from a Hunting Club Member here where I belong. There is an area within the 800 acres we hunt to shoot over 300 yards. Now I am excited. He's going to show me the area in 2 weeks.

Don

Don,

Sounds like you are ready to rock.

JD338

 

[Guest]

Yep, can't wait.

Don

 

[Guest]

Thought I would post a pic of the .192 group shot with RL25.

 

[Guest]

View attachment 300 RUM 200 AB Retumbo.JPGHere's the group shot with Retumbo that proved to hot no matter what I did to eliminate slightly wiping the case heads later. Since then I have chosen to go ahead with the RL25 Powder.