300 Rum Range Results.

Michael J. Spangler

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Sep 20, 2009
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300 Rum Range Results. Load Development Help Please

hey guys, just wanted to show some of what i've been doing. try to get a little more active on the forum

so i loaded up some of the hornady 208 grain amax bullets with a starting load of 85 grains of H1000,(just using up what was left) in a remington case with winchester large rifle magnum primers.

i wanted to mess with seating depths, so i headed to the range to give it a try. i shot some rounds loaded .020", .050", .080", .110" off the lands (measure with a hornady bullet comparator set up in my dial caliper)

i used a cheap old rest at the range and shot each load not really noticing much difference between the first 3 loads, all between 1.25" and 1.5" groups, but the .020" gave about an 11/16 group. seems promising. but this was all with a very wobbly useless rest so i'm not going to look too much into it until i get some solid resultsfrom the next load

so i went back home and cracked in to the bottle of hodgdon retumbo, and loaded up some rounds with the same specs but 85 grains of retumbo.

i headed back to the range and shot the load that was .110" off the lands. my first round with no rest. this is the flyer, then shot the other 4 rounds with a bean bag my uncle handed to me. this definitely helped out. and this was the result.

IMG_5575.jpg


when that was done i adjusted the scope of a MOA and right and MOA shot the load that was .080" off the lands, all of course with my new found friend the bean bag. this was the result

IMG_5576.jpg


now the load that was seated .050" off the lands was shot rushed at 200 yards in low light conditions, being hasty i really just wasted that load. so no results on that on.

i ran out of time and still have yet to shoot the load that is seated .020" off the lands. but i'm curious to see what the results will be.

i would like to be able to use a round that fits in my magazine. but if the .020" seating depth shows enough improvement i might have to forget about that.

now i guess the next step is to load up some more rounds increasing the powder charge. the seating depth to be determined, i need to shoot that last load before i go any further.

this LRS stuff is pretty **** addictive. what kind of improvement have you guys found with changing the seating depth of a bullet?
 
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Michael, I shoot the 210 berger in a 300 RUM and it likes .020 off the lands I use the hornady tools that you mentioned as well. I use to load for the 208 amax in my RUM when i had the factory sendero barrel on it. Do you have an extended box mag or is your rifle factory? the reason i asked is because when I shot the 208 Amax I didn't have the oal tools I just seated the bullet just long enough to clear the magazine and the 208 shot very well .

Note: Get you a good rest so you don't blow that sweet load because of the wibble wobble:)

Bigbuck
 
hey bigbuck.

i don't have an extended mag it's just factory.

i'm going to invest in a nice rest soon. one of the many things i need to buy.
it's tough to keep up with two very addictive hobbies.

i think next week i'll be able to take the rifle again and shoot the last load at .020" off the lands to see how it compares to the other seating depths.

then i'll start working on powder increases. i guess it's time to get a chronograph.
does it ever end?

i sure hope not.

thanks for the quick reply man. it's always cool to see what everyone else is getting for results compared to me.
 
ok here are the results from the next few loading and range sessions. all shot with dead calm conditions. around 85 degrees outside at 100 yards

Range Time

the first two pictures are just copies of what i posted on here.

picture 3 was a group .020" off the lands... not pretty at all. but this was shot with a bag in the rear and my range bag in the front, where i normally use the tripod.

so i then shot picture 4 with a bag in the rear and the tripod in the front. which was seated a few thousandths too long for a functioning magazine length. seems pretty nice

i knew i should re shoot the .020" from the lands to be sure it was the load and not the change in shooting set up that was off. so i did

picture 5 is a load that again was .020" from the lands, shot with a rear bag and my tripod to see what i could do. i found this interesting because a load of 85 grains of H1000 seated .020" from the lands produced a very nice group in my first session.

pictures 6-10 are bullets seated to magazine lengthish (about .165" from the lands) with powder charges from 86 grains of retumbo to 90 grains of retumbo. all shot with a rear bag and a tripod

not quite sure of how to interpret these results.

it seemed that my loads anywhere from .080" to .150" from the lands worked out well last time that i shot.

now coming back with new loads at .165" from the lands i can't seem to get a decent group.

this seems to be a chicken or the egg questions. seems to make sense to find the proper seating depth, then mess with powder charges. but i guess i'm just stuck on where to go next. any help interpreting results would be awesome.
i'm not worried about getting everything perfect in any rush, i'm not hunting with the gun and i'm not shooting competition so i'm having just as much fun working out a load, as long as i get the range time.

thanks a bunch guys
 
Looks like you've been havin some fun burin powder:)

It seems to me that the .150" off the lands with 85.0 grains of retumbo could possibly be tweaked into a good load. have you tried 85.5 grains of retumbo yet at that seating debth ? My rifle loves 85.5 but that's not written in stone for anyonelses
rifle . Just another option maybe .

what are you using to measure the powder charge with and are you trickling ? Is your cases trimmed to length are you neck sizing after you have fire formed your brass or bumping your sholder back .001-.002 thous. ? This will help you get that little bug hole .

One last question . Is your barrel free floated all the way down except about 2 inches from the recoil lug ?

Can you give a brief run down of your rifle and what mods it has ? this will help everyone give the best info that they can .
Some of the other guys will chime in shortly i'm sure.

Bigbuck
 
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the rifle is a remington SPS tuned by dan bedell
it is free floated on an HS precision stock. harris bipod. leupold mark 4 3.5-10 illuminated mil dot reticle. not sure the make but it has a brake on it. factory trigger re-worked.

the brass is once fired, trimmed, flash hole deburred, neck sized only.

using WLRM primers. i'm trickling all of the charges to exact weight.

hope this helps. i might have to get an extended magazine now. i was worried that it might do me no good if i had to seat these suckers to the lands there would be no way the mag would be long enough, now if this load works i think the extended mag would work out fantastic.

thanks for the reply! keep em coming
 
the rifle is a remington SPS tuned by dan bedell
it is free floated on an HS precision stock. harris bipod. leupold mark 4 3.5-10 illuminated mil dot reticle. not sure the make but it has a brake on it. factory trigger re-worked.

the brass is once fired, trimmed, flash hole deburred, neck sized only.

using WLRM primers. i'm trickling all of the charges to exact weight.

hope this helps. i might have to get an extended magazine now. i was worried that it might do me no good if i had to seat these suckers to the lands there would be no way the mag would be long enough, now if this load works i think the extended mag would work out fantastic.

thanks for the reply! keep em coming

That info sure helps
good set up and good hand loading practice as well !

I never had to get a extended box to shoot the 208 A-max or the 210 sierra MK's but I did find that the extended box helped me greatly with the 210 bergers. (but I haven't tried the A-maxs since i've installed my extended box either)

Is your barrel still factory ? If it is how fast do you shoot your groups ?Are you letting it cool down waaay down before the next shot sorry if you already know all of this stuff . Just trying to help you get that jaw dropping group that we all long fore :) customs can handle the heat but when i had my sendero factory barrel on my rifle i would have to waite a while before i could get the results i was after.

From my experience and what i've read from other folkson this site, you don't have to jam the 208's to get them to shoot.

Did you try 85.5 yet sometimes that other .5 makes a difference .

Someone with more experience will chime in hopefully.

bigBuck
 
It has been my experience that the AMAX is not effected by changes in seating depth just charge weight and primer choice.

I use my backback as a rest even at the range pack it full of sweetshirts for the range. I do use a rear bag but a rolled up jacket will work just as good.
 
none of these groups were shot with any type of cool down between them.... i'm impatient. i know it's bad. the issue is mostly that i get to the range and generally have about an hour and a half before they close. so i rush... which does no good

yes the barrel is still factory. it's a very heavy barrel. not sure the muzzle o.d. i'll check when i get home.

i have not tried a .5 grain incriment yet. i was hoping to find a bracket where it shot well and move between those loads.

i've heard a lot of poeple say the amax's and also the .300 RUM in general isn't picky about seating depths.

i just figured i would see more of a difference between these powder charges, maybe a little tighter group somewhere, but they're all pretty much the same from the last session.

thanks again guys. keep em coming.
 
none of these groups were shot with any type of cool down between them.... i'm impatient. i know it's bad. the issue is mostly that i get to the range and generally have about an hour and a half before they close. so i rush... which does no good

yes the barrel is still factory. it's a very heavy barrel. not sure the muzzle o.d. i'll check when i get home.

i have not tried a .5 grain incriment yet. i was hoping to find a bracket where it shot well and move between those loads.

i've heard a lot of poeple say the amax's and also the .300 RUM in general isn't picky about seating depths.

i just figured i would see more of a difference between these powder charges, maybe a little tighter group somewhere, but they're all pretty much the same from the last session.

thanks again guys. keep em coming.

"imaptient" we have alot in common:) I know what you mean by pushed for time . I would shoot a three shot group and waite atleast 10 minutes between shots but after that it would take a long time for the barrel to cool back down as to when I first started shooting that day. I was so imatient that what I started doing is bringing along my trusty .22 bolt gun and play around with it at another target so I wouldn't watch the clock every 2 minutes(it seemed like forever) . I have no doubt that with your rifle and loading technique that you will be posting some nice pics here shortly !! Good luck..

BigBuck
 
thanks man.

i think that might be the trick. bring something else along to keep me busy.

now i just need to bring something that i don't plan on doing load development for.
i'll stick to the .22 i guess. good to practice the fundamentals anyway.
 
alright so let me know what you think

i'm going to load 3 rounds of each of the following
loaded .030" off the lands and decreasing in .030" increments away from the lands until i hit .180" from the lands. which will give me a seating depth that should function properly in my magazine
(do you think these increments are good?)

i'll take my time on a nice calm saturday from 9 am till whenever i finish. shooting the groups with a few minutes in between each shot until all are gone. i only have a 10X scope so i figured i would keep it at 100 yards, should i move out further?

should i shoot off of a rest? or stick with my bean bag/bipod setup?

chronograph? or not really worth it till i get to messing with the powder?

i plan on shooting them on individual targets, i think shooting a ladder or round robin ladder would probably prove fruitless based off of close range and no change in powder. might just end up with a big mess.

i'll post some results of what i shot on my website. maybe i can get some more help interpreting results if they're pretty close to each other.

then i can fine tune the seating depth based off of the results and what seems to be a good "node" going back through the 3 shot groupings. Should i move the distance out at this point?

when that's done i'll mess with the powder charge in the same fashion, coarse increments to fine a "node" then i can fine tune between the most accurate loads. at this point bring in the chronograph to check for ES, and SD

sound like a plan? should i make changes?
 
in my sendero, i was shooting 96grns of retumbo behind the 208 and 210 bergers. the velocity was 3150 and just using 3 shot groups, both would shoot under 1/2" at 100. I am thinking you should try to bump them up a bit. 96 in my rifle was warm but not a hot load. Jeff
 
am i right in thinking that i should determine seating depth first though? as this has a big effect on max load if i end up seated very close to the lands?

thanks again guys.

this stuff is addictive.
 
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