Thread: 284 Hammer projectiles in my 7mm-08

HI, luckily Charlie of GRT and in the forum, has decided to rerun the tests that I have done .
For those that can see the forum , the conversation is happening at this time and the commentary at this time is that special allowances do need to be built into the GRT tool for these special projectiles . look the conversation up. So far Charlie has applied a reduction of bullet friction ( -80 bar ) for the special characteristics of the projectile , and the initial pressure has been lowered to 1450 psi ( from3636 psi ) for the same reason .and Charlie ( who i believe is an expert in this discussion ) has also gone onto revise the qualities of the ADI 2208 as well . .
The OBT is now almost perfect for all measured in field parameters.
So for those that are fmilar with the GRT forum I speak off here is the link https://discord.com/channels/6210392...08252824273046
Despite the commentary from one , this is not a vanity project . This is a discussion concerning a new, and unique projectile that is behaving quite differently comparing all others, and my own testing suggests ( as does charlies rerun ) there appears to be something here .
If you get to the forum and find Charlies commentary to me , look at his own GRT workups for the load which he has included , and particularly look up the one with the OBT file attached and Charlies notes . I think you will be surprised at his conclusions . I have attached a pic of two cases from the ladder .

Grandpamac, ironically your load projection for "soft " is exactly spot on for these solid copper bullets ( i know this because they are the same results as my own testing with these projectiles ) The thing is , and this is the discussion, Hammer projectiles in the Absoulute Hammer design are not behaving like solid copper projectiles. I feel in need to repeat the point . These projectiles made by Hammer , and particularly the "Absolute Hammer" projectile seem to have the abilty to carry more velocity ( than you would expect ) without the same increases in pressure as you would expect .

How does one get these projectiles without taking hammering on the shipping? Anyone ordering some soon?

Greetings @LJPRMC,
I don't doubt for a minute that you got the same velocity for the same charge but the soft, medium and hard loads given were all at the same pressure. Use the soft charge with the medium projectile and the pressure will be borderline hot. Use the soft charge with a hard projectile and the pressure will be over max. Add another grain and, you know what I am going to say.
You may think that I am rejecting the statements on the web site out of hand. Over the years I have seen far too many claims made for magic projectiles, cartridges and rifles and only tend to believe the claims when they are backed by hard pressure tested data, something that Hammer has failed to provide. Their statements are vague, lacking in substance and above all proof.
I went out to the shed and measured one of the 139 grain Hornady Interlock projectiles that the soft data is based on. It was 28.7mm in length the same weight SST was 32.4mm. I would expect the 140 grain Hammer to be longer still. Your M700 mag is limited in length so you wind up seating all the projectiles to the same length. The extra projectile length has to go somewhere and that is down into the case. This raises pressure and is one of the reasons that Barnes recommended dropping a projectile weight with their projectiles.
Regards Grandpamac.

Book load data are always on the conservative side. From what I can see the load looks fine.
I have loaded the 143 hammer in my 7mm saum and it hauls arse. Every load I fired at a piece of paper shot through the same hole. Never did find its max load but figured at that accuracy who cares. Have shot around 6 reds with that load - they didn't like it!

Found a pics
[ATTACH]210168

Originally Posted by grandpamac

Greetings Once More,
I thought it might be useful to expand a little on how I go about setting a target velocity for handloads. First data is gathered from the pressure tested on line data put up by the projectile and powder companies. For this exercise data from what I refer to as soft. medium and hard was collated. Soft is thin jacketed flat base projectiles like the Hornady Interlock and the Remington Corelokt. Medium are the boat tail projectiles with thicker jackets like the Nosler AB and hard are the solid copper boat tail projectiles. The mediums are longer than the softs so take up more powder space and the solid copper longer still. Using AR2208, 140 grain projectiles
and adjusting for the 22" barrel max loads and velocities gives the following results.

Soft Projectiles 43.5 grains of AR2208 for 2,830 fps.
Medium projectiles 42.2 grains of AR2208 for 2,780 fps.
Hard Projectiles 41.2 grains of AR2208 for 2,740 fps.

Part of the reason for the reduced charge as you progress from soft to hard is the increased amount of case volume taken up by the projectile when seated to mag length. This occurs even if the projectile has, or the manufacturer claims have some type of trick ogive and grooves.
I recently went through this process for a friend using the Remington 140 grain projectile and AR2208. I classed the projectile as soft and able to use the Hodgdon data for the 139 grain Interlock I tested 42.5 grains of AR2208 which chronographed 2,760 fps when corrected for a 22" barrel which shot well so we stopped there.
For the Hammer projectile I would recommend a max of no more than 41.5 grains of AR2208 and expect a velocity of about 2,750 fps. Neither you or the deer will notice the difference in performance and it does not risk the rifle blowing up in your face.
Regards Grandpamac.

Firstly , I use Gordons reloading tool alot . I am very familiar with it and because i use .284 projectiles in my 7mm-08 i have loaded many different companies bullets . Neither hornady or remington make 140 gr projectiles in .284 . Nosler do make 140 accubond and i have loaded those. Your load of 42.2 grains of either hogdon ( Varget ) or ADI 2208 is hotter than my max in the same length barrell of 22inches , COAL at 2.8 , case volume at 55.3 grains
So what can I say ? . I use several loading manuals including Nosler and Hornady . I have subscriptions to other online data bases as well , but i am most confident with Gordons Reloading tool . So. heres what GRT says about 42.2 of Varget or 2208 under the 140 gr nosler accubond, its in the same game as the 140 gr Hammer absolute, over pressure. But is it really ? Obviously you say not . The thing about the accubond is that it requies twice the initial pressure to get started, unlike every other Nosler 140 gr in .284 . If you had said the nosler 140 partition or the silvertip , 42.2 gr of varget or 2208 actually does produce a velocity of 2776 fps .
So, now the discussion comes full circle . the Hammers need only 1450 psi to get started into the bore , the partition needs 3636 psi , and the accubond needs almost 8000 psi and now for the same load of 42.2 , the hammer reaches 2739 fps, a partiton style makes 2679 fps and the accubond 2816 fps and slightly over pressure . .
Gordons reloading tool predicts the following ....
Now at 43 grains the hammer is at 2794, the partition is at 2727 and the accubond is at 2861 and now at very high pressure
Now at 43.5 rains the hammer is at 2827, the partition is at 2757
now at 44.0 grains the hammer is at 2861 , and on the edge of pressure , the partition is at 2787 is still safe, but at 44.6 it meets the pressure max point and Vel =2822
my chrono matches the Hammer loads reasonably closely . and usually does with other loads as well . But i can tell your experience is different from mine and i guess thats reloading for you. The thing to note here though , is that the Hammers are being treated quite differently in GRT than all others.
I cant confirm that the treatment in the tool is absolutely correct, but then i didn,t do the adjustments, an expert at GRT tools forum did. I can say though , and i think the pics of the cases show, no obvious evidence of high pressure, and for all the readers, do you own research and if you use the info i have collected and spoken of, you do so at your own risk .
cheers
les

I think i might look into a 7mm saum ..cause my problem is fallow at 600 mts and while the 140 absolute has about 1800fps out that far, energy is heading to below 1000 ft/lbs in a hurray . As for accuracy ? your experience is the same as mine . the most accurant round i ever fired
cheers
les

Originally Posted by LJPRMC

I think i might look into a 7mm saum ..cause my problem is fallow at 600 mts and while the 140 absolute has about 1800fps out that far, energy is heading to below 1000 ft/lbs in a hurray . As for accuracy ? your experience is the same as mine . the most accurant round i ever fired
cheers
les

Greetings,
I bought a 7mm SAUM Sendero when they first came out around 2004. A very accurate cartridge. It seems to have found it's niche in F Open class shooting. The factory slowish twist and short mag do hamper it a bit but if you are building a rifle these are no problem. The low number of rounds fired in mine are rather embarrassing.
GPM.