Is Seating Depth THAT Important?

[@1clnsdime1]

I do think some projectiles are more picky on seating depth. For what we do in prs, with a good barrel and good components, just pick a velocity and find that charge. Then, try a few seating depths and roll. There is no need to burn 500rds doing a load workup.

[@The4GunGuy]

Hi 1clinsdime1! I totally agree and that's why in the beginning I said that if you're new to the sport, you'll get hung up on all these numbers, then eventually, you'll "see the light" and do exactly what you just said...And still make impacts. Thanks for watching another one my friend!

[@linkchen8245]

Love this type of content! Keep up the great works man !

[@The4GunGuy]

Hi linkchen8245! Thanks for the kind words and for watching my friend!

[@L0NGRNGE]

Great video. This is good testing to do. I ran down a massive rabbit hole doing similar testing, had similar results, couldn't really tell a difference. Biggest breakthrough was bedding my rifle (MDT JAE v-block chassis). After doing that, the thing started shooting tiny dots (centers touching) instead of blobs (edges touching) and I had, for the first time, the ability to resolve differences. I found that seating depth matters a lot in keeping a rifle in tune. DTACs would tune best actually jammed around .025" and chased for the life of the barrel while hybrids tended tune better with long jumps of .125 or more and left alone. I got the worst results with every bullet I tested flirting with the touch point (+/- .020). I think the key is to get away from the touch point to find a good tune. Small changes make a big difference in both group shape and velocity when you seat around the touch point. Takes bigger changes to make a difference once you get away from it.

[@The4GunGuy]

Hi @LONGRNGE! Totally agree that small things can make a big difference. I've thought about bedding my actions but just never have taken the time...Would make a great video though! Thanks for the input and thanks for watching another one my friend!

[@erickaracsonyi4415]

This is exactly what the Hornday podcast have been talking about. Good stuff.

[@The4GunGuy]

Thanks Erickaracsonyi4415! I've spent too much time worrying about the numbers, only to realize that the groups don't lie! Thanks for watching my friend!

[@thomashansen9390]

@@The4GunGuythey may not lie but they also don’t tell the whole truth

[@Accuracy1st]

Just going by memory the most common finding for me is the best groups are usually my worst with ES/SD. Not saying they are bad but across the board with probably all of my rifles, I have yet to have my best groups produce my best numbers.

[@rustynut1967]

It seems a lot of people chase numbers rather than group size.

[@The4GunGuy]

Hi Accuracy1st! Rustynut1967 hit the nail on the head below...And as a beginner, I did exactly that, I chased the SD's and ES's and then when I had 'good' groups I stopped, but in reality, I was doing it backwards. Now, as you so rightly pointed out, and as my results showed, the best groups were at a poorer SD/ES node. Thanks for watching my friend!

[@TexasLeverGunner]

Hybrids and even Tangents, to an extent, are not seating depth sensitive. I'd have to look at a print of a 107SMK but I'm fairly certain it's somewhere between a tangent and a hybrid. The .020 off the lands seating depth would likely print a group the same size as the others if you shot enough individual 5 shot groups. The human brain is hard wired to look for patterns and things that probably aren't there.

[@The4GunGuy]

Hi TexasLeverGunner! I agree and I think we saw that in the results here. As a beginner, I got hung up on the numbers and wasted a lot of rounds chasing them for the 'best' SD/ES/Group combo. It's only when you start to do some hard calculations around ES's that you can understand how large or small of a difference an ES range can make at distance, in fact, I've talked about that and given numbers in a few of my videos related specifically to PRS (not F-Class, which has a very different accuracy requirement). And your comment on the human brain is spot on. How many times have we looked at other shooter's impacts while checking zero at the range or before a match and then strived for that accuracy, wasting ammo in the process...Good is good enough in this sport, and I suggest that a good 60% of our misses are because of US, not our equipment or our cartridge. Thanks for the great input and for watching my friend!

[@joemass1023]

How I find my seating depth - politely PM a pro who I know shoots the same cartidge with the same components. Ask what his load and depth is. Load up 25 of those. If it groups okay with a good SD, I run it and never look back.

[@The4GunGuy]

Hi joemass1023! That will work as long as you get the results that work for your barrel and is a great starting point if not, so really good advice. Thanks for watching my friend!

[@rustynut1967]

Depends on the discipline. For PRS this would be fine with the right bullet.

[@The4GunGuy]

Hi rustynut1967! Totally agree and I think the results support your statement. Thanks for watching another one my friend!

[@levigne25]

I’m confused as to why you are choosing the best group in this case . The fact that all 5 groups are somewhat close to eachother you be better off choosing the one with the best SD’s . Muzzle velocity variation is far more important to hit percentage at long range than group size and that is a fact . If you have the program applied ballistics Analytics you can see this for yourself .

[@The4GunGuy]

Hi levigne25! This is a great example of looking at the groups and setting boundaries for your SD/ES tolerances. I used to strive for the lowest SD's and ES's but didn't take the group results into as much consideration as I should have. If you listen to people like Eric Cortina and Bryan Litz, they'll tell us the same thing, follow your groups first and live within your SD/ES tolerances, which for me are SD's under 15 and ES's under 25. Let's look at an example, if you watch my video on changing powder, I show some charts that provide bullet drop information based on 6fps, 20fps, and 50fps velocity differences, which are 0.86", 2.93", and 7.52" respectively. These differences would represent the EXTREME spread of the lowest and highest velocities in say a 12 shot string during a stage in competition, which COULD happen, but most likely would not be the case out of a 100 round match, and if it was, so be it. What I'm saying is that 1) We roll the dice hoping that the ES doesn't happen between two adjacent rounds; 2) If we get a smaller ES within every 2 shots as we make our shots, the differences mentioned about could be half or even a third, and in PRS, when we are generally shooting at a 2 MOA target (~16.75") or even a 1 MOA Target (~8.376"), we still have a very good chance of an impact up to the 25fps ES scenario. On top of that, many other factors will come into play such as wind, trigger pull, stability on the prop, cant, etc... So, to make a long story short, yes, I agree that while all those groups are 'good', and all the SD's/ES's are within MY tolerance ranges (yours may be different), I'm going to go with the best group, knowing that 1) As I erode the lands, I'll still have good groups + SD's + ES's all along the way and have a longer erosion runway until the barrel is shot out in ~3,000 rounds. Man, didn't mean to write a novel for you and hope this makes a little sense...Long day and it's late. Thanks for the comment and thanks for watching my friend!

[@levigne25]

@@The4GunGuy the bottom line is that muzzle velocity variaron has more of an affect on hit percentage than group size does and that comes from Bryan litz’s mouth . So again being that your groups are so close to eachother , I would choose the most consistent muzzle velocity .

[@pitts3219]

You changed everything under the sun on your Rimfire rifles and your preaching about being obsessed with numbers. lol

[@The4GunGuy]

Hi Pitts3219! Ha! You're absolutely correct! But those changes were due to mechanical factors more than accuracy. In retrospect, I'd be just as accurate today in 22LR if I had kept my first PRS 22LR, which was my Tikka T1x shooting ELEY Tenex, but I got caught up in the "Vudoo" wave and began my journey down disappointment lane. Also, 22LR ammo is VERY particular to the barreled action combo, which is why I'm releasing a new video in a couple days on how I found the new 22LR ammo that works in my new 22LR barrel. BUT, in centerfire, the only thing I've changed is the barrel over the years and have been shooting that same Impact Precision action since I started and across 2 calibers (I have changed, chassis and triggers, but those were for ergonomic reasons, not accuracy). I just wish 22LR was as easy as centerfire from an ammo perspective. Sorry for the novel here, but short of it is, yes, for 22LR you are correct. Thanks for watching my friend!