Need H1000 Loads for New 300 PRC

Well, loaded some 215 Hybrids today with H1000 just to see how they would perform. Keep in mind this is virgin Lapua brass and neck tension was all over the place. Not very impressive and not sure where to go next. I will say I did not see pressure signs at 80 grains so can't decide whether to keep going or stick with a lighter load. This was also only 3 shots per load so SD and ES are meaningless. Only two good groups out of 10 different loads (.5 grains between loads) is pretty disappointing. I really wanted the gun to like the 215s.

Lapua virgin brass
CCI 250
H1000 (started at 75.5 and went to 80 in .5 grain increments)
Berger 215 Hybrids
3.650 COAL ( I have no idea where this is in relation to the lands)

View attachment 273735View attachment 273736

That group with 79.5 looks good.

I would work with that load and do seating depth work, to try and bring that group into one clean hole.


Also next tension consistency will help, and after you fire form and get the barrel broken in, it will only get better.
 
Have you check your neck for thickness? You may also want to lighten up your neck tension too. Is this a new barrel? I know you are talking about new brass and you are just beginning to use them. Also probable need to work on bullet to land distance, but watch your chamber pressure. Another person was showing a group that was tight, and he was working on neck tension. Don't stay stuck on just 215, there a lot of other bullets to use. Hammer has Hammer Hunter bullet in 214grs.
 
That group with 79.5 looks good.

I would work with that load and do seating depth work, to try and bring that group into one clean hole.


Also next tension consistency will help, and after you fire form and get the barrel broken in, it will only get better.
I will find the lands tomorrow. I just arbitrarily picked COAL of 3.65 since it is a 3.850 mag.
 
I w

I was .085 off the lands at a coal 0f 3.65.

So 3.740 would put you .010" off the lands.

If you want to shoot in the lands, make a dummy round with no primer or powder at around 3.80" and chamber it, letting the lands seat the bullet where it wants to be, and then rack your bolt back removing your dummy round and measure it again and see what the OAL is. It's really best to use a comparator for this.


This will give you your max soft seat jamb measurement.

From there you can only go make it shorter to start your seating depth work.


If you are not comfortable with being in the lands, then start .010" off the lands and work back.


There is also a good article about this here.


Here is a snippet


Screenshot_20210512-063422_Samsung Notes.jpg
 
Last edited:
Interesting table you set up. Sure wouldn't want to hit the table. I would use case trays to place my weight case into. Log them on a spread sheet. Them Make on the base with finger nail polish ( like 300, or 3, or Mag, or W Mag or any code to verify the weight of the case. That way at the range if I got them mixed I could go back and get them in proper weight order. I know that it help in the ES variances.
I've setting up to do volume weight checks instead of case weight. Now reading that doesn't apply so much anymore. I know I will do both for awhile and see that takes place in velocity.
Got to get moved completely to Montana.
Mike, I have tagged a corner and 200 223 brass were re sorted. It was an excuse to have a favorite beverage!!!
 
Well, loaded some 215 Hybrids today with H1000 just to see how they would perform. Keep in mind this is virgin Lapua brass and neck tension was all over the place. Not very impressive and not sure where to go next. I will say I did not see pressure signs at 80 grains so can't decide whether to keep going or stick with a lighter load. This was also only 3 shots per load so SD and ES are meaningless. Only two good groups out of 10 different loads (.5 grains between loads) is pretty disappointing. I really wanted the gun to like the 215s.

Lapua virgin brass
CCI 250
H1000 (started at 75.5 and went to 80 in .5 grain increments)
Berger 215 Hybrids
3.650 COAL ( I have no idea where this is in relation to the lands)

View attachment 273735View attachment 273736
I think I would keep pushing them. I have a node around 3100fps with 230gr HB TGT. No pressure signs wit 31" 1:8 tube
 
Went back out today with once fired brass, H1000 and 215 Hybrids .015 off the lands. I started at 79.4 (2 foulers then 3 shot group) and went up to 80.6 in .2 grain increments. The first two shots were almost same hole. The following 3 shot group at 79.4 is whacky because I put the Magneto Speed on to get MV. I took it back off for the group at 79.6. First two were close and I rushed the third as it started to rain......I came home and pulled the remaining loads because I was getting a very faint ejector mark. Not sure you can even see it in the picture. No heavy bolt lift at all. Only have 55 rounds down the tube but have noticed velocity hardly varies from 79 - 79.5 grains.

IMG_1553.jpegIMG_1556.jpeg
 
Went back out today with once fired brass, H1000 and 215 Hybrids .015 off the lands. I started at 79.4 (2 foulers then 3 shot group) and went up to 80.6 in .2 grain increments. The first two shots were almost same hole. The following 3 shot group at 79.4 is whacky because I put the Magneto Speed on to get MV. I took it back off for the group at 79.6. First two were close and I rushed the third as it started to rain......I came home and pulled the remaining loads because I was getting a very faint ejector mark. Not sure you can even see it in the picture. No heavy bolt lift at all. Only have 55 rounds down the tube but have noticed velocity hardly varies from 79 - 79.5 grains.

View attachment 274492View attachment 274493

I like the 79.4 grs for your OCW for the time being.


Seating depth work will bring that group together.


Have you considered a small jamb? Maybe .010 - .015 into the lands?


Maybe move closer by .003 increments till touching to start with.
 
I like the 79.4 grs for your OCW for the time being.


Seating depth work will bring that group together.


Have you considered a small jamb? Maybe .010 - .015 into the lands?


Maybe move closer by .003 increments till touching to start with.
I'm not liking the 79.4 as much as I thought I would. Also think the gun may have sped up a bit as it started out higher than usual for that load....And had what felt like increased recoil. Of course I forgot my Magnetospeed.

These are all 79.4 H1000 and the 215 Hybrids starting at the lands and moving out to .040 in increments of .005. Not very impressive. I think I need to chrono and back off on the load. Hopefully can get out to do a ladder test at some distance once things dry up.

IMG_1561.jpeg
 
I'm not liking the 79.4 as much as I thought I would. Also think the gun may have sped up a bit as it started out higher than usual for that load....And had what felt like increased recoil. Of course I forgot my Magnetospeed.

These are all 79.4 H1000 and the 215 Hybrids starting at the lands and moving out to .040 in increments of .005. Not very impressive. I think I need to chrono and back off on the load. Hopefully can get out to do a ladder test at some distance once things dry up.

View attachment 275377

You will get increased pressure being "in" the lands.


.025 looks good.

As little as .003 can make a different when it comes to seating depth.


Try .022 and even .018. .015" + .003"


That .015" looks promising as well.



I had some faint ejected marks at first, then after about 20 or so rounds no more.




JLB
 
Last edited:
Top