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new 300 test loads


Jgun

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I finally made it back to the range to chrono the test rds I loaded using the donated brass from friends and members, thanks guys. I also just got an order of new production 300AAC primed brass, so you will be seeing some coming your way shortly.

First off, the case splitting that I was getting with my last loads has disappeared with all of the donated brass I used to make up these test loads, either used 300BLK marked or formed LC, or .223 brass. I have to assume the the brass I bought from Midway was not annealed properly, none of the new brass had any problems whatsoever.

  My new loads all made the major power factor that I was trying to achieve. I made major PF using, 145,155,and 175gr bullets. the 145's with 20gr of LIL GUN powder averaged 2400 fps, the 155's using 18grs LG powder averaged 2232 fps, and the 175 SMK's using 16grs LG powder averaged 2015fps. I saw indications that the 175's were pushing the pressure a little, the extractor marks seemed to be more pronounced. I also found that the 175's didn't cycle 100%. Not sure why,but I'll reduce that load a little and try them again before making any gas adjustments, since the 145's and 155's all cycled 100% with the present gas block setting, 

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  • 2 months later...

I was able to chrono my 125 gr 300BLK test loads today, Unfortunately, my hottest load of 21.5 gr of LIL GUN powder behind a Speer 125 gr TNT only gave me a best velocity of 2550 fps. I was hoping to get 2600 fps from it. I see no indications of excess pressure, so I'm thinking about trying another 1/2 grain after I have the barrel melonited. I'm starting to get into  compressed load territory here because I can't reduce the seating depth of the bullet any further without having to worry about the rd not being secure in the case. Maybe the melonite process will help the situation a little.

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Nothing wrong with compressed loading , to a point. I have seen bullets move in rds in mag. under recoil , so its a fine line on how far you can take it .

Also the pressure factor can spike with a compressed load , but its a trial & error thing , as you already know .

Did you see the loadings & COL in the last issue of G & A ?

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I haven't seen it yet. I keep forgetting to stop at the store to see if I can pick up a copy. Regarding the 300 load, when I was at the range the other day chronoing them, My friend (that originally got me into the  300) was testing some of his loads. He really likes to load his stuff hot. He was testing out of a 14.5" Noveske 1/8 twist barrel. He had some 168 gr bullets loaded with 21.5 gr (I think) of powder. He was blowing the primers right out of the cases, obviously too hot! I think that his problem was the result of the seating depth of the 168 gr bullets. His focus is different than mine, He's trying to see how powerful he can make it for maximum wounding/lethality. Anyway, I've ordered some of the new Sierra Match King 125gr 300BLK bullets and one of those Lee factory crimp dies from Midway and when they get here I'm planning to bump my loads up a little, along with trying out the crimp die. I'm really thinking that I want to build another 300BLK upper, this one minimum length (14.5"w fixed brake). I don't want to spend the money on the Noveske barrel, so I'm thinking about getting one of the Wilsons like yours.

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edgecrusher

You scanner came out better than mine did.

Jgun

I have to look for those 125 MK, I have not seen them . If you buddy wants max wound effect , spooling up a 125 TNT will do it for sure , with the 300BLK.

I believe the 125 gr. range is about the best all around bullet weight for this round & the 135 gr. MK is for longer ranges & still keeping some speed .

I have not had the time to compare the G&A loadings with mine yet , but will . There are more powders out there to use for the 300BLK than I knew about .

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With those charts Edgecrusher posted it looks like the Nosler Ballistic Tip 125gr is getting about 5-7% more velocity over the Speer and Sierra.

I know very little about reloading. I understand that not all primers and powders are created equal. To what extent those differences are, I am oblivious.

Jgun,

I would assume, based solely on my very novice understanding, that the boat tail shape and ballistic tip of the Nosler provide that extra 5% velocity you are looking for. Although, I recognize that the bullet is considerably longer and also assume that a different powder/primer would be required.

Am I anywhere close to understanding this?

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I keep getting conflicting opinions regarding the superiority of boat tail vs flat bottoms. I was able to make major PF with  plenty of margin, using the 145gr boat tails and 20gr of powder. What I have found when going from the 145gr BT's to the Speer 125gr FB's is that the extra powder needed to get the 2600 fps I would need for PF requires me to load the bullet very shallow in the case (to leave more room in the case for powder). I would not be able to use a BT bullet seated that shallow. The only reason for trying the SMK's over the Speers, is that the match kings are a longer bullet and will load with the bullet ogive closer to the lead of the rifling, hopefully giving better accuracy. I plan to try increasing the powder charge one grain, loaded behind the the SMK's. If this doesn't get me 325 PF I will start testing some 130/135's.

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Jgun,

Should of kept the ones I had in the cases I sent you , you would have test components . <laughs>

I think the SMK 125 gr. bullet will be a great shooter . Just think of the 135 gr. SMK that I sent you & take ten grains off the weight of the bullet , not much huh ! The 125 SMK should look almost the same . Long & sleek.

I like the performace of a BT  to a FB bullet , they just fly a little better to me . Not to mention , they stick right in the case when reloading . Nothing like having a tapered bullet to help start it in the case.

I will find time tomorrow to compare my notes to the loading data from G&A.

As far as the Nosler's velocity, you are right , many factors that could of contributed to the increase. I liked that loading my self , it kinda stood out .

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I had mistakenly thought that the ballistic tipped bullets were generally more expensive than the non tipped. I just took a look at the Noslers on Midway's site and see that they are comparable in price to the 125 SMK's. Although I noted in the G&A load data that the 125 Nosler's were faster than the other's, none of the bullets listed, came close to the 2550 fps I'm currently pushing the Speer TNT's to. I'm not positive because they haven't arrived from Midway yet, but I believe that the 125gr SMK's are flat bottoms and don't share the boattail configuration of the 135,150,155,168, and 175gr SMK's. If I can't push the 125 SMK's to 2600, I'll try the 125gr Nosler's and the 135gr SMK's. Thanks for the advice.

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My 125 SMK's showed up today, along with a Lee 300BLK factory crimp die.

I just did a quick check, and the extended length of the MK's works out so that when seated to the same depth as the 125gr Speer TNT's that I tested, the SMK is just about .050" from the lead of the rifling, while still fitting in the Pmag.  Next chance I get, I'm going to load them up with a little more powder and see what happens. I'd also like to try out the factory crimp die, but I'm not 100% sure how to tell when I've got enough, but not too much, crimp. It seems as though there is no adjustment to the die, only the height in which it's set in the press. Any of you guys try these type of dies before?

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Can't help ya with the die , never used or even seen one , but are you having bullet set back from feeding ?

Do you really need the crimp die or if you are just making sure , you don't have set back when in competition mode ?  (Can't blame ya there )

Getting uneven or excessive crimp can cause problems , as you know .

Call Lee or email them , they are quite helpfull.

Now you are going to make me buy some 125 MK's  . How about a photo of said SMK ?

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I tried out the crimp die in my press and it's so simple that even I can do it. no moving parts for you to adjust, the instructions say to raise the ram, bottom out the die against the shell plate in the raised position, lower the ram and then  adjust the die down 1/2 turn. The crimp is created by the shell plate putting pressure on the bottom of the crimp die which in turn squeezes the four die "fingers" creating the crimp. pretty neat actually. I am going to use it more for added insurance than anything else, I've had no indications of bullet set back, but think it's a good idea for me considering how shallow I'm seating my bullets. I'll take some pics of the bullets I'm testing and try to post them later.

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Well blow me down , its a FB bullet , You may be able to get more powder in the case with a FB bullet .

Yes I will try them. I like the TNT( I think it shot the best of my test loads) , but its made for Varmint hunting & seems a little light in the jacket .

Can't wait to order some . I put a better scope on my 300BLK today, may try it out Sunday .

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  • 1 month later...

Finally got back out to the range  to chrono my 125 gr TNT and SMK test loads.

First off the disclaimer, I consider these to be the max powder loads that will fit in the cases with these bullets, in fact the SMKs were too hot, so I don't recommend that you duplicate them, and if you do it's at your own risk.

The best loads I have are the 125 gr TNT's with 22gr of LIL GUN powder, in new Rem brass loaded to 2.150 COL. with this load I got an average MV of 2612 fps, which easily make major power factor. My loads with 125 gr TNT/22.5 gr of LIL GUN chrono'd at  2700 fps.

Unfortunately, the 125 gr SMKs, due to their longer length, had to be seated deeper into the case in order to fit the Pmags, so with the same powder loads as the TNT's, the SMK's were over pressure and blew out the primers. I strongly advise that you don't try them.  All of the loads here are compressed, including the TNT's.

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Yeah, I'm pretty happy about that. Now I know that, with this barrel config. I can make major power factor with anything from 125-175gr bullets.  I'm planning to buy some bulk of the 125 TNT's and load so that I can test for groups and get my holdovers down for 200-300m. I realize that this power factor is just an arbittrary number and really has little real world usefulness. I am planning to back the 125 SMK loads off to 21gr and chrono them just to see what kind of fps I can get. I think, based on the appearence of them, that they might make a more accurate rd than the TNT's but will have to find a safe load with them before I can shoot for groups. I'm hoping to pick up a 14.5" barrel within the next few months. It will be interesting to see how much the MV is lowered from the shorter barrel and tighter twist.

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I have a family friend that owns a reloading business. He has been bitten by the 300Blk bug, and swears by it now. I am patiently waiting on all your results before I bombard him with thousands of round of brass.

PS. http://www.loadxammo.com/

It's a smaller shop, but Steve puts out thousands of round every week. He completely supplied my Police Academy with pistol ammo. Great plinking ammo. You can buy ammo he has on hand, order new ammo, or send him your brass and ask for a reload. Great guy!

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