Thanks, I talked to Rich yesterday, he is a good dude, brass is already inbound, I wanted ADG anyway, just suffered from, ahem, minor reading comprehension deficit, I'm blaming the dog.
-
Having trouble using the site?
Contact support
Sherman 7 MAX
- Thread starter BCX
- Start date
My current impass is solved, but I'm interested in how this works. I don't actually know in detail how the smith will use the dummy round. Obviously the SAUM case will fit in a Max chamber, but do the dimensional differences (taper, shoulder angle, shoulder position) not make a difference for his use? I think you are saying/implying that the fit may be imperfect, yet still fine for the purpose.
With a Max case dummy, I will seat with bullet shank-boattail at the neck-shoulder junction; with a SAUM case for a pseudo-Max dummy, would you seat longer than the SAUM junction (e.g. add the difference in Max vs SAUM n-s jct position) ?
Last edited:
Interested in how much bump you find is required to get your bolt to close properly in your rifle?
Also if possible, comparison with virgin brass from your previous lot, of base-to-datum.
[Assuming the problem is not trim length]
The case length for the 7 MAX and 7 Saum are identical. When you fire form from SAUM to MAX, you are changing the shoulder angle and removing the taper. Necks are same length from my measurements w 7 SAUM and new lot of brass w 40 degree shoulder. I don't have the reamer prints infront of me to compare.
Per Mr Sherman, 7 MAX chamber length is 2.025 w a trim length of 2.015. 7 SAUM max case length is 2.035 w a trim length of 2.025.
For what it's worth:
My new lot of ADG/Sherman 7 Max 40º (h.s. "300 MAX") : avg=2.008, min=2.007, max=2.0095, N=20.
My new lot of Norma 7mm SAUM : avg=2.020, min=2.0190, max=2.0235, N=20.
Thinking about asking LRI if they will machine a blank case holder from Giraud Tool. Anyone else done this?
My new lot of ADG/Sherman 7 Max 40º (h.s. "300 MAX") : avg=2.008, min=2.007, max=2.0095, N=20.
My new lot of Norma 7mm SAUM : avg=2.020, min=2.0190, max=2.0235, N=20.
Thinking about asking LRI if they will machine a blank case holder from Giraud Tool. Anyone else done this?
Both cases are unfired. SAUM is Norma, Max is ADG/Sherman. The Max neck-shoulder and shoulder-body junctions are somewhat rounded & indistinct, possibly result of hydroformed Max? So kind of difficult to get a precise neck measurement. Shoulder angle, body length, and body taper differ (by design).
Sorry, in the photo the cases are not quite aligned at the base.
Last edited:
Looks like the classic neck down and get shorter cases scenario.
Not really a big deal.
I am using a 21st C. turning mandrel (T28, o.d. = 0.282) to size neck i.d.
1. Size virgin case with 0.313 bushing, and the mandrel slips in by hand with practically 0 friction -- too big.
2. Size same case with 0.312 bushing, mandrel does not slip in by hand.
3. Size i.d. with mandrel die & T28.
4. Seat a Berger 0.284 190
5. Measure neck o.d. = 0.314
With this batch of brass, I might start with 0.312 (it passes the desk-press check), see how that goes, and experiment with < 0.312, depending on how it unfolds once I can fire them.
With finding powder what it is these days, RL 23 is also an option. I run my 7 SAUM w/58g of RL 23 and 183 SMK. I get 2993 fps with a 29" barrel. Early on got to 3100 fps with 61g of RL 23, but started getting clickers after a few reloads so brought it down to 2993 getting SD under 5. ADG brass has been great. Going on 14 reloads on my first batch. 183 SMKs group beautifully.
Man out running my max with 183 smk 28 inch. I need better powder but it isnt like we can just order what we need now haha
Got some Hornady 190gr ATIPs, and did some comparing vs. the Berger 190 LRHT.
1. Measure bullet OAL: ATIP=1.661, LRHT=1.586, difference is 0.075"
2. Using Sinclair comparator, measure bullet base-to-ogive: ATIP=0.875, LRHT=0.836, difference is 0.039"
3. Seat each in sized virgin ADC/Sherman brass, such that shank locates just above the neck/shoulder junction (by eyeball).
4. Measure COAL: ATIP=3.140, LRHT=3.100, difference is 0.040"
5. Measure CBTO: ATIP=2.353, LRHT=2.350, difference is 0.003"
That is, within error of seating alignment by eye, the CBTO is equal. Which is interesting.
1. Measure bullet OAL: ATIP=1.661, LRHT=1.586, difference is 0.075"
2. Using Sinclair comparator, measure bullet base-to-ogive: ATIP=0.875, LRHT=0.836, difference is 0.039"
3. Seat each in sized virgin ADC/Sherman brass, such that shank locates just above the neck/shoulder junction (by eyeball).
4. Measure COAL: ATIP=3.140, LRHT=3.100, difference is 0.040"
5. Measure CBTO: ATIP=2.353, LRHT=2.350, difference is 0.003"
That is, within error of seating alignment by eye, the CBTO is equal. Which is interesting.
I have a few a tips left
I’ll have to try them in my new 5R barrel and see how they do and if they hold together.
I shot a few 180 ELDM’s to break it in and so far they did ok.
59.5 of R26 seems to kick ass with any 180 or 190 in all three barrels I’ve run so far.
I’ll have to try them in my new 5R barrel and see how they do and if they hold together.
I shot a few 180 ELDM’s to break it in and so far they did ok.
59.5 of R26 seems to kick ass with any 180 or 190 in all three barrels I’ve run so far.
From this point on, i won't be testing anymore 7MM bullets unless they are Steel head approved HAHAHA.
Finally tested the 190 A-Tip at 1k today along w Berger 195 and a few Berger 190 i had leftover from last year... Berger to the win again. No vertical w the Berger. Accuracy over BC
Finally tested the 190 A-Tip at 1k today along w Berger 195 and a few Berger 190 i had leftover from last year... Berger to the win again. No vertical w the Berger. Accuracy over BC
Berger 190 LRT was spot on at a mile last year. I believe Steal Head has tested all 7mm BC out to 2400-2600. I know advertised BC is higher on the A-Tips but showed vertical at 1K so I'm out. I will burn this barrel out w Berger's.
And old brass hahaha. All that new brass is primed w FED 215 m.
And old brass hahaha. All that new brass is primed w FED 215 m.
I was shooting the 183’s last weekend out to 1900ish and I got a similar BC.
Overall I’m starting to like that bullet.
I was mag feeding them with considerable jump and they kicked ass.
I had the same findings.
A tip had the better BC.
Berger 190’s had better vertical and none blow up.
I got the 190 out to two miles last year.
They did great but spotting was certainly a challenge.
Dam 2 miles. I need to make a trip out and we have a battle of the 338ssss hahaha
79 mils on average.
Going out tomorrow with my buddy and his 338 Norma
Shooting from a mile to possibly 4K possibly.
265 and 285 badlands.
That’s why I stayed with 7 saum.
7max is a great cartridge but for my uses I really needed more grains in the bullet if I was going to upgrade.
Those little and efficient 7mm sure are a lot of bang for the buck though!
338’s and bigger quickly become
338’s and bigger quickly become
Well I just started load development but 2900+ with the 285 and 3000+ with the 265 seems pretty easy.
I am trying to arrange for LRI to machine a case holder for the Giraud Power Trimmer from a blank, while they have the (rented) 7 Max reamer. Obviously this depends on availability of the blank(s), and LRI agreeing to do the work. Still waiting for replies on both, but if anyone wants to pile on, it might be worth doing a couple-few of these while they have the tooling set up. Let me know if you are interested.
Last edited:
Similar threads
