7mm mag loads and bullet recommendations

[kck]

You belted cartridge old timers are killing me . I kid, I kid. Matt, I take it you dig the bore rider throat. I’ve got a customer asking about a 7-300 and I guess someone mentioned a bore rider throat to him but not sure what info he was given. I’ve kinda stayed away from them in larger bullets getting pushed fast due to assumed finicky loads and quicker throat wear but I wouldn’t mind giving one a shot. Also, you’re F’in Send It stickers are loved by all here.

[rut-ro]

The 140 gr accubonds are awesome. Every deer I’ve shot with them have all been DRT. 40 yards to 320.

[trophy8]

You belted cartridge old timers are killing me . I kid, I kid. Matt, I take it you dig the bore rider throat. I’ve got a customer asking about a 7-300 and I guess someone mentioned a bore rider throat to him but not sure what info he was given. I’ve kinda stayed away from them in larger bullets getting pushed fast due to assumed finicky loads and quicker throat wear but I wouldn’t mind giving one a shot. Also, you’re F’in Send It stickers are loved by all here.

I was pretty skeptical of the BR. But I gave in and got it. It’s pretty awesome. Wasn’t finicky at all. Super fast. I gained a bunch of speed switching from h1000 to retumbo and then the BR. Might not get more barrel life since I’ll run it harder. But certainly extends one compared to non BR if running the same load.

[Wayspr]

Don't mean to derail this thread but could you elaborate more on what a "bore rider throat" is?

[trophy8]

Don't mean to derail this thread but could you elaborate more on what a "bore rider throat" is?

Basically a +P chamber. Stepped chamber. Eases the bullet into the lands instead of just biting right off the bat if that makes sense. I believe Defensive Edge were the first to do them with the 338 Edge chamber in their rifles.

[bboswell]

I have to stray from the pack here.


For a one load for anything gun I would go with 160g Partitions all day but the Accubond would be a close second.


For whitetail size game I got better results with the 140's pushed fast though.

[Rhettsker]

160 accubonds out of a fast 7mm is bad news for whatever you shoot.

^^^this^^^. I hunted with a 7mm mag for several decades using the 160 AB. For a do all round(deer to large african plains game) its about as good as you can get.
R

[westtexducks]

I have to stray from the pack here.


For a one load for anything gun I would go with 160g Partitions all day but the Accubond would be a close second.


For whitetail size game I got better results with the 140's pushed fast though.

This is kinda what I am leaning towards get a box of both and see which it like better. If I want to chase moose later I may pick up a box of 175 partitions then but for lower 48 the 160s I think will be the ticket especially elk and big muleys.

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[tx2019]

The faster you push them, the more expansion you will get. IMO, the best results for deer sized game with the Barnes is to go light for caliber and push them as fast as possible.

Definitely. This is especially true with the TTSX, which will expand faster than the TSX.

[Capp35]

For deer, mine loves 139 gr Hornady.

[H-D]

I'm in the process of working up a load for my APR 7mag.
I'm using 168 Accubond long Range projectiles on top of Retumbo in a Norma case.
Just yesterday I found my ogive OAL to the lans and am going to back off a bit now and test a few lengths for accuracy.
I'm at just over 3k fps currently and am extremely happy thus far with this rifle and how it shoots

[bboswell]

I'm in the process of working up a load for my APR 7mag.

I'm using 168 Accubond long Range projectiles on top of Retumbo in a Norma case.

Just yesterday I found my ogive OAL to the lans and am going to back off a bit now and test a few lengths for accuracy.

I'm at just over 3k fps currently and am extremely happy thus far with this rifle and how it shoots

I loaded ABLR’s for 2 different 7mm rifles. They wanted a LOT of jump!

[flyinstroke]

I loaded some Berger 168 VLD's over Retumbo and getting 2950 FPS. 2 cow Elk that were shot didn't like it. I can't speak for Moose. Everything but 1 of the cow Elk has been bang flop. The cow that ran made it 40 yards on her feet and another 250 yards down the side of a mountain.

[Hardware]

The faster you push them, the more expansion you will get. IMO, the best results for deer sized game with the Barnes is to go light for caliber and push them as fast as possible.

Backwards. Speed them up to increase damage.

This^^

Barnes need to be pushed hard

I agree when velocity drops below 2600fps. Also with the TSX being tougher it needs to be slowed down at shorter shot distances to still work as intended. I've copied some information below that I referenced when deciding to load the cartridges for my current setup.

"Velocity
This has the greatest effect on hydrostatic shock. Put simply, the higher the impact velocity, the greater the shock. Velocity is also the most influencing factor in hydraulic shock, having a huge bearing on the size of the internal wound channel.

Hydrostatic shock, in bore sizes from .243” up to .338”, begins to lesson at impact velocities below 2600fps and most modern high velocity sporting cartridges including the magnums gradually lose shocking power beyond 300 to 350 yards. Of the thousands of animals harvested during TBR tests, 2600fps has been the most common cut off point with repeatable results (reactions) occurring when deliberately testing the impact velocity of 2650fps versus the impact velocity of 2550fps.
High velocity is not however a sole factor to be worshipped and held above other factors. For example, if velocity is increased too far without increasing bullet weight, the surface tension of water within the animal can cause so much resistance as to overcome the energy of the bullet. Ultra-high velocities can then also lead to shallow penetration. Generally speaking, the high velocity cut off point for small bore bullets used on medium game is around 3150fps. If for example we are using a 140 grain 7mm bullet at an impact velocity of 3250fps, chances are that even if the bullet penetrates vitals, the animal may still run some distance.

One factor to be very careful of with ultra-high velocity conditions is to not blame a delayed kill exclusively on ‘bullet blow up’. For example, if we were using the same 140gr 7mm bullet and the entry wound did indeed show signs of wide entry wounding and surface bullet blow up (or possibly blow back), even though this is undesirable performance, we still need to investigate further if we are to truly understand factors at play. In this instance, once the animal is recovered, it is important to study the vital organs and determine whether they were actually destroyed. If the vitals were destroyed, we can then conclude that the bullet did its job (even if in a less than desirable manner) but without hydrostatic shock.

A noticeable change in hydrostatic shock occurs as bullet diameter is increased to .358” (such as the .35 Whelen) and larger bores (see bullet diameter). With the medium and large bores, hydrostatic shock can occur on our medium game species at velocities as low as 2200fps. Fast incapacitation can remain evident at velocities as low as 1800fps depending on bullet designs. Below 1800fps, the wider the bore the better. Further to this, there are also highly traumatic pistol bullet designs such as the Hornady XTP.

Frangible bullets tend to produce coma at much lower velocities than traditional hunting bullets (see bullet construction). With frangible bullets at low velocities, instant coma may be due to hydraulic shock causing blood pressure spikes in the brain as suggested by Hornady ballisticians. In other instances, coma can follow very shortly after impact due to multiple pain centers being disrupted to such an extent that the animal must go into coma. That said, frangible bullets may also send out particles which strike the CNS directly.

When testing hydrostatic shock on Bovines, I have discovered that impact velocities of 2600fps with suitable bullet weights (and construction) produced instant poleaxe in a repeatable manner. However, in many instances Bovines would attempt to rise, the action of attempting to rise resulting in increased blood loss with death following within seconds.

Bullet weight versus game weights
If the bullet is too light for the intended game it may simply lack enough kinetic energy to cause hydrostatic shock, meeting far too much resistance on impact. This a common occurrence with the .22 centrefires but can also occur in any small bore cartridge especially the large magnums when using soft, light for caliber projectiles. If the bullet is driven too fast and lacks sufficient weight, it can also fail to initiate hydrostatic shock (see Velocity).

Less obvious, is the result of using a bullet weight that is too heavy for the intended game. If the projectile contains too much momentum, the bullet may fail to meet enough resistance to impart energy where it is required i.e. the ribs through to the spine. Wound channels may be as wide as a lighter bullet however; the hunter may find that game run a long way before succumbing to the shot. These factors can create many difficulties for the hunter when selecting an appropriate cartridge and bullet as a certain level of momentum is required if the bullet is expected to penetrate into vitals from any angle or give satisfactory performance on a variety of game body weights.

Quite often a .30 caliber 180 grain hunting style bullet is simply too stout and carries too much momentum to initiate hydrostatic shock / rapid coma on lean bodied deer - even at magnum velocities. The bullet may produce a nice mushroom and seemingly adequate internal wounding; however game may run a long way before expiring. A simple change to a 150 or 165 grain bullet can make all the difference in these instances. That or a change in bullet construction such as changing from a core bonded bullet to a fast expanding design like the Hornady SST. Energy retention as a result of heavy bullet construction and the retention of momentum can be even more of a problem in the .338 bore which has many projectiles designed specifically for Elk hunting. Furthermore, many hunters use match bullets in the .338 for long range hunting, some of which are simply hopeless on game.

Projectile construction
The third factor that effects hydrostatic shock transfer and counteracts bullet weight while also having the capacity to counteract impact velocity is bullet construction. For example, the stout Sierra .30 caliber 180 grain Pro-Hunter, whether driven from the .308 Winchester or .300 Win Mag creates a large internal wound on light or lean bodied deer, yet it can retain too much momentum to initiate hydrostatic shock on these animals and kills can be very slow. The same can be said of some of the stout core bonded designs such as the 180 grain Interbond along with the Barnes TXS bullets. By simply changing to the 180 grain Speer BTSP, the 180 grain SST or 178 grain A-Max, a faster kill can be obtained. These projectiles are soft and frangible. The Hornady A-Max in particular can produce fast coma at impact velocities of 2000fps or lower where the ProHunter shows a clear cut off point at an impact velocity of 2550fps.

In contrast, as game body weights reach 90kg (200lb) and above, stout bullets begin to come into their own, meeting a great deal of resistance on impact. Hydrostatic shock is still absent at impact velocities below 2600fps, however the heavy resistance of larger bodied medium game helps initiate immense trauma and broader internal wounding than on lighter game body weights, resulting in a kill that is delayed by only a few seconds, as opposed to up to 45 seconds.

The further you shoot, the softer your bullet needs to be in order to affect a wide wound and fast killing at low velocities. This is discussed at length within my long range hunting book series. At closer ranges, a tougher bullet may be needed in order to ensure adequate penetration. There may also be times when you need to dual load which is again discussed within the book series but also within the knowledge base. An example of dual loading might be as an example, having a 140 grain Nosler Partition in the top of the magazine of your 6.5x55 rifle while under this, you have three or four 143 grain ELD-X bullets ready for long range work.

Perhaps the greatest challenge hunters now face when choosing bullets, are the challenges presented by homogenous copper bullet designs. These are the toughest bullets on the market and due to their design, are unable to shed weight and lose momentum for maximum energy transfer. Some designs boast petal loss as a means to aid energy transfer but such features can make the bullet even worse, causing the shank of the remaining bullet to pencil through game creating narrow wounding, especially at lower impact velocities.

Homogenous bullets work best at high impact velocities. The bullet makers know well that momentum is a problem and in more recent years have generally worked towards offering lighter and then lighter still bullet designs. This reduction in weight and bullet length greatly aids wounding so long as velocity can be kept high. Homogenous copper bullets tend to initiate hydrostatic shock like other bullet designs at impact velocities above 2600fps providing the bullet weight is properly matched to game weights. In the .30 caliber, this can mean dropping right back to a 130 or even a 110 grain bullet design. Wounding generally remains adequate to 2400fps. Below 2200fps, all bets are off, especially if shot placement is less than ideal. Game may run long distances and may not allow the hunter the opportunity for a follow up shot.

The greatest benefit of homogenous copper bullets is that they penetrate well. The Barnes TSX for example, creates both excellent wounding and penetration when properly matched to game weights and used in high velocity cartridges out to moderate ranges. This is a homogenous copper bullet at its best, tackling tough animals from varying angles. But to say that one can eat up to the bullet hole (in the absence of lead toxicity) can be rather misleading. The current Tipped TSX design (used in high powered cartridges) can cause gut ruptures as a result of hydraulic forces, spreading gut material into meat. Those concerned about meat damage or meat fouling need to understand this - bullets kill via destruction of tissue. We can’t always have it both ways."

[Shane]

Hardware, the article you posted confirms that copper bullets like the TSX do better with more velocity, and that they suck at lower velocities. In your earlier post you mentioned that you don't push them as fast as you could because of their poor performance - in response to ttaxidermy's (accurate) comment that the bullets don't perform well on deer-sized game. The responses to your comment about not pushing them all pointed out (accurately) that you need to push them faster, not slower, to improve the performance of those bullets.

I have heard more negative than good reports from people that use those type of bullets. Most report poor expansion, tiny hole pass throughs, not as much hydrostatic shock (due to most of the energy being expended after the bullet passes through the animal), etc.... That's what the article you posted is talking about. And that's the reason I don't shoot those bullets. I'm sure they are accurate. And weight retention is great. But terminal performance in a deer's body is what matters most, and they aren't as good as lead/copper bullets are for what matters most.

I'm not trying to attack you are argue with you. And maybe I'm not reading all of your posts here correctly. But it seems like you aren't clear about how those bullets work. Just trying to help clear it up, if that's the case. If I'm misreading what you've been trying to say, then please disregard my comments here. Just trying to help is all.