# 300 wm assistance



## JDog (May 21, 2004)

I'm relatively new to reloading and just starting with the .300 wm. the cartridge diagram shows a minimum case length of 2.620. I'm ok there as my cases are all within .003" of this number. My cases are once fired from my rifle and I'm neck sizing only. 

Next I loaded a 180 grain hornady SST. I loaded the bullet so that my crimp (using the lee FCD) is in the middle of the crimp, or maybe just a bit further back (longer col). When I measure this cartridge, the COL is 3.36-3.37 versus the 3.340 from the cartridge diagram. Is this ok?

I marked up the dummy round with marker, loaded it and I'm not on the lands. 

I'm trying to find a good load so using h1000 I've loaded 4 rounds each from 76 grains to 81 grains (max) using .5 grain increments. Will this longer COL be an issue or can I shoot these starting with the 76.0 rounds and watch for usual pressure signs? Also, these rounds chamber with no problems now.


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## woods (Dec 3, 2011)

Hey JDog

Everything you are doing sounds OK



> My cases are once fired from my rifle and I'm neck sizing only.


Neck sizing is fine as long as you don't have a "crush fit" when you chamber a round. IOW your cases have started expanding and after 2 to 4 reloads (varies according to your load and chamber dimensions) they will be come harder to chamber. You will know this when you take an empty case and chamber it and the bolt is harder to close.

Once you develop a crush fit you will need to size the case body and push the shoulder back a little. It is important at that time that you do not push the shoulder back too far, .001" to .002" is about right. You can do this without measuring tools by benching your rifle while sizing the cases and sizing until the crush fit just starts to become less. You want your cases to chamber in the field but repeated pushing the shoulder back too far can result in a case head separation which can be dangerous.



> I loaded the bullet so that my crimp (using the lee FCD) is in the middle of the crimp, or maybe just a bit further back


You do not have to crimp your bullets. Crimping is necessary when you are reloading for an autoloader, for big boomer with lots of recoile where the bullet could seat deeper from contact with the front of the magazine or if you have very light bullet grip. If you take your loaded case and put it point down on the bench and can push the bullet deeper then you need to crimp.

The Lee Factory Crimp Die is an excellent die and the only way I will crimp. It does not need a cannelure to crimp into. IOW you can crimp anywhere on the bullet surface. If your seating die has a crimping feature then those types of crimps do need a cannelure but not your LFCD. Be advised that repeated crimping will shorten your case length a little everytime when you chamfer off the crimp remains on the next loading. It is possible that by the 6th or 7th loading the LFCD will not crimp anymore because your case is too short and out of the operating range of the LFCD collets.



> When I measure this cartridge, the COL is 3.36-3.37 versus the 3.340 from the cartridge diagram. Is this ok?


Yes as long as you are not getting too close to the lands and the loads will fit in your magazine. If you load too close to the lands then your pressures will increase, the farther from the lands you load (up to a certain point) the less pressure and thus less velocity you will have. Plus IME once you get inside .010" jump to the lands you will get flyers from velocity variances.

Best to get a *tool* that will tell you how far from the lands you actually are. In most 300 win mags the magazine is the limiting factor and you find that you will have a long distance to the lands even when loading at max length to fit your magazine. There are ways to use what you have on your bench to determine this but IME they are not as accurate. The 2 tools I recommend are


R-P Products C.O.L. E-Z Check - [email protected] 318-424-7867 (there is an underscore between the 2 r's in the e-mail address)
Hornady OAL tool - from Midway or whatever and you will need the modified case in your caliber ( http://www.midwayusa.com/product/570611/hornady-lock-n-load-overall-length-gage-bolt-action , http://www.midwayusa.com/product/69...ngth-gage-modified-case-300-winchester-magnum )



> I'm trying to find a good load so using h1000


I have better luck with RL22 but H1000 is a good powder



> watch for usual pressure signs


right way to do it, start low and look for case head marks and stiff bolt lift


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## JDog (May 21, 2004)

*Fantastic*

Woods,
Thanks a ton for taking the time to provide such a detailed reply. This confirmation and new information helps me out a lot! I've loaded .223 and .40 cal, but when I'm dumping 76+ grains of powder in a win mag cartridge the pucker factor goes up a bit!

I'll see how the accuracy is with this batch and then try some without the crimp and see if anything changes. Then I'll start messing with COL unless I get lucky and I get reasonable accuracy at the current depth. I've shot some 3/4" 100 yard groups with this rifle (Sendero) so I'm hoping I can find a good load with my current component setup. The rifle clearly shoots better than I do!

Thanks again!


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## coogerpop (Sep 3, 2009)

RL 22 is the best powder I have found for this caliber...with 180 gr.Hornaday bullets...


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## mrsh978 (Apr 24, 2006)

*300 win*

rl 22 is good, imr 4350, h and imr 4831 are my go to powders for that weight. i reload for 6 different win mags. play around with them all to see how your gun vibrates best. 75 gr of rl 22 gets real close quick and seat bullet just off the lands.


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## JDog (May 21, 2004)

*Some results*

I got to the range today. First group of my initial starting loads (76.0 grains) grouped at .62 for four shots! I was stoked. The rest of my loads were ok but nothing spectacular until I got to 1 grain below maximum (80.0) and then I put three shots into one ragged hole. The group measured .252! :dance: I did have one flyer that opened it up to over an inch, but as I kept pulling the trigger and not seeing the hole change I began to rush things. I'm hoping that 's all it was.

No pressure signs at 80 grains. Bolt cycled easily, primer looked normal.

Next up, I want to load 10 of the 80.0s and see if I can repeat the results. If so, it'll be time to go into mass production! If not, I'll see if bullet seat depth and/or crimping changes things and also take a closer look at the 76.0 load.

Fingers crossed!


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## mrsh978 (Apr 24, 2006)

*300*

just came back from playing with 2 rifles. both dialed in well (180 gr bal tip) using 76 grains rl22. started low and worked up-not showing real hot load yet, but more poweder shrunk groups-i see this a lot, groups shrinking the more i push them . hope this helps.


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## mrsh978 (Apr 24, 2006)

*end results*



mrsh978 said:


> just came back from playing with 2 rifles. both dialed in well (180 gr bal tip) using 76 grains rl22. started low and worked up-not showing real hot load yet, but more poweder shrunk groups-i see this a lot, groups shrinking the more i push them . hope this helps.


note : see thread on hunting side of 32" aoudad-the lady used my rifle that is a oneholer-made a 377 yd shot. once i told her where to place crosshairs, it was just a matter of squeezing trigger. she was shocked that she could shoot something that far and HIT it.! wish i could explain that to other hunters i ve had-most cant hit the car door they just got out of.....


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## 27contender (Dec 22, 2008)

Great picture! It is as if I cannot see her legs!

Good info, they all like different set ups! Makes life interesting.

R


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## JDog (May 21, 2004)

JDog said:


> I got to the range today. First group of my initial starting loads (76.0 grains) grouped at .62 for four shots! I was stoked. The rest of my loads were ok but nothing spectacular until I got to 1 grain below maximum (80.0) and then I put three shots into one ragged hole. The group measured .252! :dance: I did have one flyer that opened it up to over an inch, but as I kept pulling the trigger and not seeing the hole change I began to rush things. I'm hoping that 's all it was.
> 
> No pressure signs at 80 grains. Bolt cycled easily, primer looked normal.
> 
> ...


So I loaded 10 at 76gr and 10 at 81gr. I didn't have great groups. Some good, but not great. I was bummed. Then after thinking more about things and discussing with friends I realized I did not clean my rifle before this last range trip. It had a lot of rounds through it. So I loaded 10 more at 76gr and went back today. I got a .97" that put four in .45" or one ragged hole. I'm going to hunt with these this year. I'll also start messing with the oal and see if that tightens it up any more in the off season, or if I can at least get 5 without the flyer.

So I learned an obvious lesson: clean your rifle before testing a load! Duh.


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## Lezz Go (Jun 27, 2006)

I have Reloader 22 in 1 and 5 pound cans. The one pound cans are $18 and the 5 pound cans (2 left ) are $89. Just FYI.


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