338 Allen Xpress, RL33 load development

jonthomps

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Interesting. I'll have to keep playing around with RE-33. My initial accuracy wasn't very good (in a 300NM) so I switched back to H1000. Sounds like I need to stick with it.
 

Fiftydriver

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Depending on your throat set up and what bullet weight your using, I would thing RL33 may be a bit to slow for some applications with the 300 NM.

H-1000 certainly would allow you to work up to top working pressures in the 300 NM much easier then with RL33.
 

Chas1

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100.0 gr......................2886 fps
102.0 gr......................2923 fps Already topped retumbo load in velocity
104.0 gr......................2969 fps
105.0 gr......................3003 fps
106.0 gr......................3036 fps 100% load density

106.0 gr produced the very first hints of an ejector ring so I stopped there.

Kirby, 100% load density. I have a question but first some base line info. Test rifle 338AX you built with 31" Krieger Barrel 1-10 twist, 300 gr Bergers atop RL-33 using Lapua brass, COAL 3.8915 and near as I can tell about 0.005 off lands, at sea-level (Florida) early morning temp 79 degrees. I took your advice and started load development at 95 gr and worked up. Results as follows:

95 gr.....2627 fps
96 gr.....2645 fps
97 gr.....2687 fps
98 gr.....2722 fps
99 gr.....2752 fps
100 gr...2798 fps
101 gr...2823 fps
102 gr...2856 fps
103 gr...2899 fps
104 gr...2947 fps

primers look good, pockets are tight, bolt lift and extraction effortless and no ejector marks at all. I knew I might be getting close on case capacity so when I loaded with 104 gr I listened carefully for any powder crunching...and there was none. Given results I thought I try 105 gr next and then 106 gr and stop there, however when I loaded case with 105 gr and seated bullet I heard an ever so slight, slight powder crunching, almost as if I removed a half dozen kernels it may not have crunched. So when you say 106gr-100% load density are you getting a slight crunching, how do you know if your at 100% load density and am I already there at 105gr ?
 

Tumbleweed

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Kirby, 100% load density. I have a question but first some base line info. Test rifle 338AX you built with 31" Krieger Barrel 1-10 twist, 300 gr Bergers atop RL-33 using Lapua brass, COAL 3.8915 and near as I can tell about 0.005 off lands, at sea-level (Florida) early morning temp 79 degrees. I took your advice and started load development at 95 gr and worked up. Results as follows:

95 gr.....2627 fps
96 gr.....2645 fps
97 gr.....2687 fps
98 gr.....2722 fps
99 gr.....2752 fps
100 gr...2798 fps
101 gr...2823 fps
102 gr...2856 fps
103 gr...2899 fps
104 gr...2947 fps

primers look good, pockets are tight, bolt lift and extraction effortless and no ejector marks at all. I knew I might be getting close on case capacity so when I loaded with 104 gr I listened carefully for any powder crunching...and there was none. Given results I thought I try 105 gr next and then 106 gr and stop there, however when I loaded case with 105 gr and seated bullet I heard an ever so slight, slight powder crunching, almost as if I removed a half dozen kernels it may not have crunched. So when you say 106gr-100% load density are you getting a slight crunching, how do you know if your at 100% load density and am I already there at 105gr ?
For what it's worth, a little trick I learned on this forum was to set your case on a vibratory tumbler to get max case capacity. Here's what I do with a couple cartridges that are right at or near 100% load density.
Charge them one at a time and seat the bullet about 50-75%. Fire up the tumbler and hold the case head down on the corner of the tumbler for about 7 seconds. Fully seat your bullet at this point. Seems to help a lot for me on those cases that are really full.
 

Timber338

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... however when I loaded case with 105 gr and seated bullet I heard an ever so slight, slight powder crunching, almost as if I removed a half dozen kernels it may not have crunched. So when you say 106gr-100% load density are you getting a slight crunching, how do you know if your at 100% load density and am I already there at 105gr ?
Not answering for Kirby, but in my experience with compressed loads including RL-33 with my 338 RUM, I will get slight crunching as I approach 98-99% capacity as the bullet is pushing the powder around the sides of the bullet.

After you seated the bullet could you shake the case and hear the powder shake just a little? If so then your just under 100% if not then you're right at it. Either way you are very close to 100%.
 

Chas1

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For what it's worth, a little trick I learned on this forum was to set your case on a vibratory tumbler to get max case capacity. Here's what I do with a couple cartridges that are right at or near 100% load density.
Charge them one at a time and seat the bullet about 50-75%. Fire up the tumbler and hold the case head down on the corner of the tumbler for about 7 seconds. Fully seat your bullet at this point. Seems to help a lot for me on those cases that are really full.
After giving it a lot of thought I think I'm going to load up 4 more rounds at 105.0 grs and follow your suggestion and see if I hear any crunching when I seat the bullet the 25%. Thanks for the info.
 

Chas1

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Not answering for Kirby, but in my experience with compressed loads including RL-33 with my 338 RUM, I will get slight crunching as I approach 98-99% capacity as the bullet is pushing the powder around the sides of the bullet.

After you seated the bullet could you shake the case and hear the powder shake just a little? If so then your just under 100% if not then you're right at it. Either way you are very close to 100%.
Not really hearing any powder shake. I think your right I'm probably right at 100%. I'll see what results I get with 5 rounds loaded to 105.0 but I'll probably stay around 104.2 as that should get me in at around 2950+fps and see what kind of grouping I get. Thanks for the input.
 

Chas1

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Shot the 5 rounds loaded to 105.0 gr. No ejector marks, loose primer pockets, easy bolt lift and extraction. Average 2966 fps for 5 rounds. Placing the case on tumbler did the trick as once loaded I was able to again hear powder shake. Great suggestion, thanks.
 

phorwath

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Re: RL33 load development, bullet seating depth, ES & SD

Just chronographed some MVs with RL33 yields in my 30/375 S.I. This is the 375 Ruger blown out to minimum body taper, 40* shoulder, necked down to .308 caliber. Shooting the 215gr Berger Hybrid at MV ~ 3060fps.

I was seeing ES of up to 50fps for 3 shots fired during load development with bullets seated at the lands and just off the lands (0.010" jump off the lands). However I'd noticed during case fireforming that the bullets that were jammed hard into the lands were generally all producing MVs with low ES, at varying RL33 powder charges.

So I loaded three maximum loads (87.7gr RL33) with the 215gr Berger Hybrids jammed 0.012" into the lands, and fired them over my triplicate chronographs. This yielded an ES of 9 and a SD of ~4. Very happy with these numbers. The low ES and SD is consistent with what I was seeing while fireforming cases with bullets jammed hard (up to 0.021") into the lands, so I have more confidence than just these last 3 shots over the chronographs.

RL33 was producing good velocity, but I was having trouble with elevated ES and SD. After reviewing the data previously collected during fireforming and just after fireforming, it became evident that ES was very consistently low with the bullets jammed.

Kirby said ES improved as the bullet jump to the lands decreased. In my case, I had to jam the bullets into the lands to see the improvement. This is the only rifle I currently use RL33 in, so this is my only 1st hand experience with RL33, bullet seating depths, and ES/SD.
 

phorwath

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Re: RL33 load development, bullet seating depth, ES & SD

No. I didn't experience significant differences in accuracy or POI. Here's group measurements from 3 separate loads - all 3-shot groups at 280yds.

88.5gr / bullet jammed 0.010" = 1.375"
88.5gr / bullet touching lands . = 1.25"
87.6gr / bullets jumped 0.007" = 1.50"

POI was basically identical for all 3 loads. 26" Krieger barrel in a BAT HR action.

I consistently had low ES with these bullets jammed firmly into the lands.
 

jonthomps

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Re: RL33 load development, bullet seating depth, ES & SD

No. I didn't experience significant differences in accuracy or POI. Here's group measurements from 3 separate loads - all 3-shot groups at 280yds.

88.5gr / bullet jammed 0.010" = 1.375"
88.5gr / bullet touching lands . = 1.25"
87.6gr / bullets jumped 0.007" = 1.50"

POI was basically identical for all 3 loads. 26" Krieger barrel in a BAT HR action.

I consistently had low ES with these bullets jammed firmly into the lands.
Interesting. I was having the same problem (high ES) using RL-33 in my 300NM. I'll have to try this and see what happens.
 

RockyMtnMT

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Have not done any temp testing with it, but it has been a very consistent powder for us with the cartridges that need slow powders. Pretty much always loads up nice and has given very good es.

Steve
 

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