Compressed Loads

Written by Sierra Bullets Ballistic Technician Duane Siercks

Here at Sierra, the Tech Room personnel field numerous calls and e-mails on a wide variety of questions regarding reloading, shooting, and trajectory situations. There are some questions that have become very frequent. I will touch on one of these at this time.

Compressed Loads

When reloading, a common situation that arises will be a load that fills the cartridge case to the extent that when the bullet is seated, it actually comes in contact with the powder charge and may actually compact the charge to an extent. I have had many callers remark that they did not feel this was correct or that it automatically made the load dangerous. Not necessarily so. If you are using a powder that has been tested in that cartridge and with that bullet weight, start at the minimum load listed and increase the powder charge in relatively small increments. Then, always watching for any signs of excess pressures, if the powder charge begins to fill the case to the level where the bullet touches the powder be certain that the load does not exceed published data. If pressures look good, the load is probably going to be fine. The compression usually occurs with the slower powders.

If you have any questions, don’t hesitate to give us a call.

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19 Responses to Compressed Loads

  1. Jimmy Askew says:

    I am trying to find data for your 350 grain , 375 target bullet. I have the 50th an. edition. it does not give any info above 300 g. Sincerely. jimmy_askew@sbcglobal,net


  2. Nathan Coombs says:

    I want to know the load data using a 85 grain sierra boat tail hollow point.. my dilemma is I have hogdon H8531SC powder can I use it with this bullet and how many grains should I start with..? Thank you for your time..


  3. Steve says:

    I received 500 rounds of Sierra 80 gr MK in 22 cal. I’m shooting a 22-250 with a 26 in barrel that has a 1/8 twist. Up till now I have only had access to horndy 75 gr hpbt, which has been shooting quite well with H414 and H380. What would you recommend for your Sierra 80’s, I love Sierra Bullets. I shoot your 52 gr MK in my 1/12 twist 22-250, and I can assure you, it’s hard to tell if it’s just one hole or not. I am fortunate to have a good selection of powders, but like everyone, there are some I can’t get. I have a large supply of H380, Varget, RL Pro 2000, and several Imr powders IE 4064, 3031,4895,4831


  4. Jon says:

    You guys have any load data around the 300 blackout by chance? I’ve got a few thousand Sierra 125 GR Spitzers and can’t find any info for them (H110 powder)


  5. Robert says:

    Do you have any load data for 6 BR Norma with your 107’s ?
    Thanks Robert


  6. Robert says:

    Looking for load data for the 6.5 creedmoor


  7. Rob says:

    Hi I’m loading up some .223 rounds using Sierra 69gn HPBT match heads. I have Lyman 49th edition and this shows load data for VV N140 as start 23.4gn and do not exceed at 26.0gn.
    I have loaded 5 rounds each in .2gn increments starting at 23.4gn, however at 24.6gn I could feel the powder crunch slightly when seating the bullet. Should I be worried about this load being compressed?
    Lyman did note that this range included a compressed load.
    I stopped loading at 25.0gn
    Load data
    Case PPU (new)
    Primer CCI small rifle
    Powder N140
    OAL 2,260

    Load is for use in AR15 strait pull.


  8. Shaun says:

    Im ran into the same issue on max load for Ar 69gr sierra match tipped. 25.8gr of win 748, could hear the powder as i seated bullet to 2.260. Has me a little worried if load data is correct.


  9. Jonathan says:

    I am looking for load data for 300 Win Mag both in the 220 gr and the 190 gr HPBT MatchKing. Do you have that available?


  10. Hello,
    I, too, am loading the .223 using the 77g TMK (2.260 OAL) and VV N140 powder. I started with 20 g powder and increased slowly looking for the best grouping. The Berger manual said the max load for this combination was 22.4gr whereas the Lapua manual said 25.5 gr was max. As I increased powder charge to 23gr, I started to notice that the seating die left an annular ring around the ogive of the bullet. I am using the Redding Competition micrometer adjust seating die. This ring became more distinct as the charge increased. I know that these are compressed loads, but I am wondering if the compression is placing enough pressure on the bullet/seating die interface to actually distort the bullet. Thanks for your input.


  11. KEN says:

    My best opinion is to get the 6thh edition.


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