.300WM Load development

[axarob44]

I shot this today and would like to know what way do you guy's think I should go. I'm thinking load a couple rounds on either side of the 69.7gr but what do you think of the 70.9gr group? I think I may have pulled that last shot. The two previous shots were one hole almost. I don't know enough about OCW to say one way or another if I might have a node at 70.9 and 69.7. Whats some other opinions? should I shoot the 70.9 again?

The specs are: 300WM with new Norma Brass, Berger 210gr LR-HPBT, Reloader 22, CCI BR2, CBTO .020" off the lands

 

[samson7x]

I'd shoot the 70.9 again if you think you pulled. I've been doing 5 shot groups but I don't know if that's common practice. Were these shot at 100yds or 200? I've read where some folks say that the heavier bullets don't settle until 200yds. Not sure if there is any truth to that so hopefully someone here can expand on it. I'm new to 300wm.

 

[axarob44]

Yes, they're all 100 yards. I'm going to do the 70.9gr over. I wish I would have loaded 5 instead of 3

 

[cruze5]

i would reload the 2 on the fast end of loads again. 5 each 70.9/ 71.3

 

[MtnCreek]

I haven't been doing ocw all that long and not good at reading them... To me, it looks like you have a node around 69.5 and another starting around 71.3. If you're not seeing pressure, might want to see what 71.3 and up looks like.

 

[axarob44]

OK, did a little more testing today. The lower charges didn't really present anything spectacular. The heavier ones did show some promise. Shot the 71.3gr and it did well and also the 71.5 really made a jump that I don't know what that means really. Except for the one shot I pulled, it looked good. I'm kind of concerned with the pressure signs higher up. The only pressure signs I'm getting is a slight cratering and ejector swipe. No heavy bolt lift at all. The ejector swipe is noticeable, but the primer doesn't look bad at all, it is still rounded on the edge. I just checked also and the primer pocket is still tight. This is my first go at magnum reloading though. If any one can comment I would appreciate it. I'm going to load a group of 71.4 and maybe 71.6 depending on what I hear about the pressure. You can kind of see the ejector mark by the "300"

I didn't move the the scope or anything with that last 71.5 group,

 

[STI_1911_Guy]

Reloader 22 works great but it is temp sensitive so if you are seeing pressure signs right now you are one warm day away from trouble. With one of the more temp tolerant powders i might say ok but otherwise I would back off. With a magnum running an OCW test increments should be around 1/2gr increments otherwise you are not changing enough of a percentage to make a difference in a "timely" fashion. You are looking for a series of charges that give you a constant POI (69.5-71.3) not necessarily the best group. To me it looks like 70-70.5 grains is right in the middle without pressure. I would run that on a couple 5 round groups and try it out at distance.

 

[NukeMMC]

Have you thought about H1000? My last 300wm shot 190s well with RE22 but shot the 208AMAX better with H1000. With RE22 I ran 70.6-71.0gr under the 208 but 76.6-77.0 with H1000. The 190s gave me 3050fps and 2925-2950 with the 208s in an A191 chamber.

Not sure what your chamber or rifle is, but the only pressure sign you're getting is the cratered primer that I can see and that may just be your firing pin-to-bolt needing a better fit. As for the errant rounds on 71.5 and 69.8, were they the first shots? I have seen more than 1 rifle that will "toss" the first round up to a minute out of group when shifting ammo or load.

Story to back it up: At Range 1 in Quantico between Virginia Regional and Interservice in 91. The guy running the test shed has an M14 test fixture where the rifle is clamped in a sliding base and fired by a cable. Puts in one of our Navy M14s and shoots a test group at 300yds with M852. It shoots about 2". He then switches to M118 Special Ball, and says it will hit about 3" to 2-o'clock. Sure enough, first shot goes right where he said, then the next 4 shoot into about 3.5" just about on top of where the M852 shot. Says it's pretty normal. He swaps out gas piston and the Special Ball shoots inside 3" and the M852 still shoots 2", but sure enough, first shot goes 1 minute out at 2-o'clock. I spent about 4-6 hours in the test shed and learned TONS about making the M14 (and MK2-1) shoot. Still have the MK2-1.

 

[axarob44]

Chief, that's what I think I'm probably going to do tomorrow, pick up some H1000. I wasn't aware that RL-22 had such problem with temperature sensitivity. It was about 70 degrees here today, but it does get quite a bit hotter here in Ohio. The pressure signs I'm seeing, shouldn't the primer be more flattened and cratered more? I did read that with the magnum that you will have more pressure problems long before your primer shows it. Well, I don't feel the bolt being heavier and the fired case extracts easily and re chambers. I popped a primer and seated a new one and the pocket is still tight. But, if I'm going to run into a problem when it's 90 degrees, I'm not sure what to do. STI 1911 says to shoot the the 70.0-70.5 but I'm not sure what that's going to do for me. How am I going to shrink the groups down? Seating depth? I hate to just settle on something mediocre because this rifle is very accurate with FGGM and Hornady 178ELDM factory ammo. I just want shoot a heavier bullet. By the way those fliers in those two groups were the first shots in the string

I had this rifle before I started reloading so I'm not quite sure what GAP did as far as chambering this rifle.

 

[NukeMMC]

I had this rifle before I started reloading so I'm not quite sure what GAP did as far as chambering this rifle.

Call them and ask what the chamber is. You can certainly shrink (or expand) groups with seating depth, especially with a VLD style bullet. I never shot the Berger 210, but my AMAXs liked it best no more than .010" from the lands.

 

[axarob44]

This is kind of confusing and contradictory about the powder usage. It's an excerpt from American Rifleman about the adoption of the various .300WM loads for the US Navy NSW





" The M852 (7.62x51 mm NATO) cartridge, which featured a Sierra 168-gr. MatchKing bullet, “was authorized [in 1990] for use in combat by snipers by the Army and Navy JAG offices.” But, as the NSWC-Crane documents mention, “Due to the JAG decision [about Open Tip Match bullets] and accuracy concerns, it was decided that a 190 grain MatchKing-type HPBT projectile would be pursued instead of the 185 grain FMJ projectile [from Lapua].” Parks’ actions “paved the way” for adoption of the Sierra 190-gr. MatchKing. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/assets.americanrifleman.org\/media\/2901862\/hero7.jpg"}[/IMG2]








With the bullet selected, the following propellants were evaluated for use in the new load: Accurate 3100, IMR-4350 and IMR-7828, and Reloder 19 and 22. The latter two were found to be least affected by temperature, maintain safe chamber pressures and provide “statistically better” accuracy.
As cited in the NSWC-Crane documents, performance specifications for the load called for: “(1) the use of a 190 grain HPBT match projectile; (2) the use of Reloder 19 or 22 propellant; (3) commercial 70-30 alloy brass case; (4) a commercial match quality primer; (4) a nominal velocity of 3,000 f.p.s; (5) pressure limits within SAAMI at -40° F., 70° F., and 125° F.; and (6) an average extreme spread of no greater than 2.25" at 200 yards., the maximum allowable individual extreme spread is 3.5".” After testing of Crane Division, NSWC-constructed ammunition was completed, a procurement action was initiated. Federal Cartridge Co. was awarded the contract in 1992.
s well-established and, thus, got the nod. Talking recently with Hoffman, he stated that, in hindsight, he wished that the 210-gr. MatchKing had been selected. New at the time of testing, he now prefers it over the 220-gr. version.


I'm sure this has been flogged to death in other locations on this site but I thought it was kind of relevant for this topic


I'm going to call GAP next week


Full article
https://www.americanrifleman.org/art...-mk-248-mod-1/

 

[Fishkat]

I've just finished load development for my 300wm, 26" barrel, 210 VLD's , Norma brass, Fed Match Mag primers and using Retumbo. Nice low node at 74-75 gn and and 76.5gn gave me close to a one hole three shoot group. Ran it higher/ hotter and found another nice load but there were some signs of high pressure. If you have an interest go to Primal Rights website and under the articles tab they have an excellent write up and pictures concerning pressure signs.

 

[axarob44]

Fishkat, Did you have a compressed load with that charge? I'm not sure whats the story is but Redding says no compressed loads with the Competition bullet seater die

just looked at the Berger Manual. Looks like your load would be under 107% fill ratio

I already read that Primal Right article but I'm going to look at it again

 

[axarob44]

I just looked , under magnification ,every piece of brass I've shot in this test and every case has an ejector mark and primer cratering in the same spot, every one, lowest to highest charge. No ejector 'wipe' or 'swipe' just a mark from comtact.

Should I see if I can work with this going a little higher or should I just move on to H1000. I did just get a pound

STI 1911 suggested 70 to 70.5. Im going to go with that and see

 

[STI_1911_Guy]

I prefer H1000 for its extreme temp stability and I believe its a great powder for the 300 win mag. If you do go that route then i recommend 77.0 gr of H1000. I havent seen a rifle that wont shoot 77 +/- .5 gr with the 208-215 class bullets.

 

[axarob44]

I prefer H1000 for its extreme temp stability and I believe its a great powder for the 300 win mag. If you do go that route then i recommend 77.0 gr of H1000. I havent seen a rifle that wont shoot 77 +/- .5 gr with the 208-215 class bullets.

Well, I loaded up a short series of rounds with the H1000 at 76.8, 77.0, 77.3, and 77.5gr. all of them shoot so well that I think I'm done messing around. I seated the the bullet to SAMMI 3.340" COAL. I am more than satisfied with this set-up! I looked at a couple sources to make sure I wouldn't have any problem with this seating depth with this charge, and Nosler actually has this exact load on their website so I went ahead with it. No pressure problems at all. I'll chrono soon. Thank you for the help!!

 

[NukeMMC]

Glad the H1000 is working well for you.

As for the NSWC Crane development of the A191 round, you have to remember that happened in the late-80s to early 90s. H1000 wasn't proven then. Not sure it existed then or not. I do remember in 91 we were given the remnants of Crane's testing of D46 170gr Lapua bullets for 7.62 rounds (after the JAG rulings were released). They shot well, just not as well rifle-to-rifle as the SMKs. Also remember that Crane is developing ammo that consistently shoots well across literally hundreds of rifles in both the NSW and Match inventories (this was before Crane was the SOCOM Depot supplier). That same document detailed the attempt to use the 185gr D46 to replace the POOR-performing spun-nose ammo, but its long-range accuracy wasn't as good as desired. I remember shooting hand-me-down A170, which was the spun-nose 308/168gr Federal Match (before Gold Medal, red/white boxes). That stuff SUCKED about as bad as Special Ball. The D46 was about the only decent match FMJ on the market at the time, so it was natural to try it.
Pretty sure you'll find the 190/220gr SMK was relied on heavily because it is more length tolerant than the 210. Again, there are hundreds, if not thousands of rifles/barrels/chambers this ammo has to consistently shoot thru. From the MK248 Mod 1 Detail Spec:

3.5.3 Cartridge overall length. (M102) [The nominal overall length of the assembled cartridge shall be 3.500 inches maximum, 3.450 inches minimum] in accordance with drawing 53711-8330252.
The distance from the cartridge case head to the 0.300 inch diameter datum on the projectile ogive shall be controlled to within ± 0.010 inches. The nominal overall length and the distance from the cartridge case head to the 0.300 inch diameter datum on the projectile ogive of the assembled cartridge shall be established, within the above limits, by the manufacturer to meet performance requirements.​

Keeping the ogive in a +/-.010" band and OAL in a +/- .050" band across millions of rounds!

 

[axarob44]

Glad the H1000 is working well for you.

As for the NSWC Crane development of the A191 round, you have to remember that happened in the late-80s to early 90s. H1000 wasn't proven then. Not sure it existed then or not. I do remember in 91 we were given the remnants of Crane's testing of D46 170gr Lapua bullets for 7.62 rounds (after the JAG rulings were released). They shot well, just not as well rifle-to-rifle as the SMKs. Also remember that Crane is developing ammo that consistently shoots well across literally hundreds of rifles in both the NSW and Match inventories (this was before Crane was the SOCOM Depot supplier). That same document detailed the attempt to use the 185gr D46 to replace the POOR-performing spun-nose ammo, but its long-range accuracy wasn't as good as desired. I remember shooting hand-me-down A170, which was the spun-nose 308/168gr Federal Match (before Gold Medal, red/white boxes). That stuff SUCKED about as bad as Special Ball. The D46 was about the only decent match FMJ on the market at the time, so it was natural to try it.
Pretty sure you'll find the 190/220gr SMK was relied on heavily because it is more length tolerant than the 210. Again, there are hundreds, if not thousands of rifles/barrels/chambers this ammo has to consistently shoot thru. From the MK248 Mod 1 Detail Spec:

3.5.3 Cartridge overall length. (M102) [The nominal overall length of the assembled cartridge shall be 3.500 inches maximum, 3.450 inches minimum] in accordance with drawing 53711-8330252.
The distance from the cartridge case head to the 0.300 inch diameter datum on the projectile ogive shall be controlled to within ± 0.010 inches. The nominal overall length and the distance from the cartridge case head to the 0.300 inch diameter datum on the projectile ogive of the assembled cartridge shall be established, within the above limits, by the manufacturer to meet performance requirements.​

Keeping the ogive in a +/-.010" band and OAL in a +/- .050" band across millions of rounds!

That's why I went with the Berger 210 LR/HPBT and not the 210 VLD. I wasn't sure what chamber it has (still have to call GAP) and didn't know how much room I had to play with for tuning the seating depth with a VLD and magazine length constraints. I know all the factory ammo that was SAMMI length shot really well. This is the first time I've dealt with compressed loads and I see in a lot of the manuals they list a lot of compressed loads, and they say that a lot of loads do there best when compressed . That's why I don't understand why both Redding says not to do compressed load with their Competition seating die and LEE recommends having a custom seating plug made for the specific bullet. Well, I know why it could be a concern, but you would have to be really cranking a lot of powder to deform the the stem/plug, but you would think if it's common occurrence they would design around the possibility of having to compress the powder when seating. The first batch of loads I used (reluctantly) the Redding die, this new batch I did with the LEE seating die.

It really bugs me to take measurements from the tip of the bullet to judge seating depth, but I'm assuming it's not critical when loading with this amount of jump anyways. I did take the seating plug out of the die and used it as a sort of comparator and the consistency wasn't too bad. we'll see when I shot them